openstack-manuals/doc/glossary/glossary-terms.xml

<?xml version="1.0" encoding="UTF-8"?>
<!DOCTYPE glossary [
<!ENTITY % openstack SYSTEM "../common/entities/openstack.ent">
%openstack;
]>

<glossary xmlns="http://docbook.org/ns/docbook"
  xmlns:xi="http://www.w3.org/2001/XInclude"
  xmlns:xlink="http://www.w3.org/1999/xlink"
  version="5.0"
  xml:id="openstack_glossary"
  role="auto">
    <title>Glossary</title>
    <info>
        <legalnotice>
            <para>Licensed under the Apache License, Version 2.0 (the
                "License"); you may not use this file except in
                compliance with the License. You may obtain a copy of
                the License at</para>
            <para>
                <link
                    xlink:href="http://www.apache.org/licenses/LICENSE-2.0"
                    >http://www.apache.org/licenses/LICENSE-2.0</link>
           </para>
            <para>Unless required by applicable law or agreed to in
                writing, software distributed under the License is
                distributed on an "AS IS" BASIS, WITHOUT WARRANTIES OR
                CONDITIONS OF ANY KIND, either express or implied. See
                the License for the specific language governing
                permissions and limitations under the License.</para>
        </legalnotice>
    </info>
    <para>This glossary offers a list of terms and definitions to define a
    vocabulary for OpenStack-related concepts.</para>
    <para>
      To add to OpenStack glossary, clone the <link xlink:href="
      http://git.openstack.org/cgit/openstack/openstack-manuals"><literal>openstack/openstack-manuals</literal>
      repository</link> and update the source file
      <filename>doc/glossary/glossary-terms.xml</filename> through the
      OpenStack contribution process.
    </para>

  <glossdiv>
    <title>Numbers</title>

    <glossentry>
    <glossterm>6to4</glossterm>
      <indexterm class="singular">
          <primary>6to4</primary>
      </indexterm>
      <glossdef>
        <para>A mechanism that allows IPv6 packets to be transmitted
        over an IPv4 network, providing a strategy for migrating to
        IPv6.
        </para>
      </glossdef>
    </glossentry>

  </glossdiv>

  <!-- .A. -->

  <glossdiv>
    <title>A</title>

    <glossentry>
      <glossterm>absolute limit</glossterm>
      <indexterm class="singular">
          <primary>absolute limit</primary>
        </indexterm>

      <glossdef>
        <para>Impassable limits for guest VMs. Settings include total RAM
        size, maximum number of vCPUs, and maximum disk size.</para>
      </glossdef>
    </glossentry>

    <glossentry>
      <glossterm>access control list</glossterm>
      <indexterm class="singular">
          <primary>access control list (ACL)</primary>
        </indexterm>

      <glossdef>
        <para>A list of permissions attached to an object. An ACL specifies
        which users or system processes have access to objects. It also
        defines which operations can be performed on specified objects. Each
        entry in a typical ACL specifies a subject and an operation. For
        instance, the ACL entry <code>(Alice, delete)</code> for a file gives
        Alice permission to delete the file.</para>
      </glossdef>
    </glossentry>

    <glossentry>
      <glossterm>access key</glossterm>
      <indexterm class="singular">
          <primary>access key</primary>
        </indexterm>

      <glossdef>
        <para>Alternative term for an Amazon EC2 access key. See EC2 access
        key.</para>
      </glossdef>
    </glossentry>

    <glossentry>
      <glossterm>account</glossterm>
      <indexterm class="singular">
          <primary>accounts</primary>
        </indexterm>

      <glossdef>
        <para>The Object Storage context of an account. Do not confuse with a
        user account from an authentication service, such as Active Directory,
        /etc/passwd, OpenLDAP, OpenStack Identity Service, and so on.</para>
      </glossdef>
    </glossentry>

    <glossentry>
      <glossterm>account auditor</glossterm>
      <indexterm class="singular">
          <primary>account auditor</primary>
        </indexterm>

      <glossdef>
        <para>Checks for missing replicas and incorrect or corrupted objects
        in a specified Object Storage account by running queries against the
        back-end SQLite database.</para>
      </glossdef>
    </glossentry>

    <glossentry>
      <glossterm>account database</glossterm>
      <indexterm class="singular">
          <primary>account database</primary>
        </indexterm>

      <glossdef>
        <para>A SQLite database that contains Object Storage accounts and
        related metadata and that the accounts server accesses.</para>
      </glossdef>
    </glossentry>

    <glossentry>
      <glossterm>account reaper</glossterm>
      <indexterm class="singular">
          <primary>account reaper</primary>
        </indexterm>

      <glossdef>
        <para>An Object Storage worker that scans for and deletes account
        databases and that the account server has marked for deletion.</para>
      </glossdef>
    </glossentry>

    <glossentry>
      <glossterm>account server</glossterm>
      <indexterm class="singular">
          <primary>account server</primary>
        </indexterm>

      <glossdef>
        <para>Lists containers in Object Storage and stores container
        information in the account database.</para>
      </glossdef>
    </glossentry>

    <glossentry>
      <glossterm>account service</glossterm>
      <indexterm class="singular">
          <primary>account service</primary>
        </indexterm>

      <glossdef>
        <para>An Object Storage component that provides account services such
        as list, create, modify, and audit. Do not confuse with OpenStack
        Identity Service, OpenLDAP, or similar user-account services.</para>
      </glossdef>
    </glossentry>

    <glossentry>
      <glossterm>accounting</glossterm>
      <indexterm class="singular">
          <primary>accounting</primary>
        </indexterm>

      <glossdef>
        <para>The Compute service provides accounting information through the
        event notification and system usage data facilities.</para>
      </glossdef>
    </glossentry>

    <glossentry>
      <glossterm>ACL</glossterm>
      <indexterm class="singular">
          <primary>ACL</primary>

          <see>access control list</see>
        </indexterm>

      <glossdef>
        <para>See access control list.</para>
      </glossdef>
    </glossentry>

    <glossentry>
      <glossterm>active/active configuration</glossterm>
      <indexterm class="singular">
          <primary>active/active configuration</primary>
        </indexterm>

      <glossdef>
        <para>In a high-availability setup with an active/active
        configuration, several systems share the load together and if one
        fails, the load is distributed to the remaining systems.</para>
      </glossdef>
    </glossentry>

    <glossentry>
      <glossterm>Active Directory</glossterm>
      <indexterm class="singular">
          <primary>Active Directory</primary>
        </indexterm>

      <glossdef>
        <para>Authentication and identity service by Microsoft, based on LDAP.
        Supported in OpenStack.</para>
      </glossdef>
    </glossentry>

    <glossentry>
      <glossterm>active/passive configuration</glossterm>
      <indexterm class="singular">
          <primary>active/passive configuration</primary>
        </indexterm>

      <glossdef>
        <para>In a high-availability setup with an active/passive
        configuration, systems are set up to bring additional resources online
        to replace those that have failed.</para>
      </glossdef>
    </glossentry>

    <glossentry>
      <glossterm>address pool</glossterm>
      <indexterm class="singular">
          <primary>address pool</primary>
        </indexterm>

      <glossdef>
        <para>A group of fixed and/or floating IP addresses that are assigned
        to a project and can be used by or assigned to the VM instances in a
        project.</para>
      </glossdef>
    </glossentry>

    <glossentry>
      <glossterm>admin API</glossterm>
      <indexterm class="singular">
          <primary>admin API</primary>
        </indexterm>

      <glossdef>
        <para>A subset of API calls that are accessible to authorized
        administrators and are generally not accessible to end users or the
        public Internet. They can exist as a separate service (keystone) or
        can be a subset of another API (nova).</para>
      </glossdef>
    </glossentry>

    <glossentry>
      <glossterm>admin server</glossterm>
      <indexterm class="singular">
          <primary>admin server</primary>
        </indexterm>

      <glossdef>
        <para>In the context of the Identity Service, the worker process that
        provides access to the admin API.</para>
      </glossdef>
    </glossentry>

    <glossentry>
      <glossterm>Advanced Message Queuing Protocol (AMQP)</glossterm>
      <indexterm
          class="singular">
          <primary>Advanced Message Queuing Protocol (AMQP)</primary>
        </indexterm>

      <glossdef>
        <para>The open standard messaging protocol used by OpenStack
        components for intra-service communications, provided by RabbitMQ,
        Qpid, or ZeroMQ.</para>
      </glossdef>
    </glossentry>

    <glossentry>
      <glossterm>Advanced RISC Machine (ARM)</glossterm>
      <indexterm class="singular">
          <primary>Advanced RISC Machine (ARM)</primary>
        </indexterm>

      <glossdef>
        <para>Lower power consumption CPU often found in mobile and embedded
        devices. Supported by OpenStack.</para>
      </glossdef>
    </glossentry>

    <glossentry>
      <glossterm>alert</glossterm>
      <indexterm class="singular">
          <primary>alerts</primary>

          <secondary>definition of</secondary>
        </indexterm>

      <glossdef>
        <para>The Compute service can send alerts through its notification
        system, which includes a facility to create custom notification
        drivers. Alerts can be sent to and displayed on the horizon
        dashboard.</para>
      </glossdef>
    </glossentry>

    <glossentry>
      <glossterm>allocate</glossterm>
      <indexterm class="singular">
          <primary>allocate, definition of</primary>
        </indexterm>

      <glossdef>
        <para>The process of taking a floating IP address from the address
        pool so it can be associated with a fixed IP on a guest VM
        instance.</para>
      </glossdef>
    </glossentry>

    <glossentry>
      <glossterm>Amazon Kernel Image (AKI)</glossterm>
      <indexterm class="singular">
          <primary>Amazon Kernel Image (AKI)</primary>
        </indexterm>

      <glossdef>
        <para>Both a VM container format and disk format. Supported by Image
        Service.</para>
      </glossdef>
    </glossentry>

    <glossentry>
      <glossterm>Amazon Machine Image (AMI)</glossterm>
      <indexterm class="singular">
          <primary>Amazon Machine Image (AMI)</primary>
        </indexterm>

      <glossdef>
        <para>Both a VM container format and disk format. Supported by Image
        Service.</para>
      </glossdef>
    </glossentry>

    <glossentry>
      <glossterm>Amazon Ramdisk Image (ARI)</glossterm>
      <indexterm class="singular">
          <primary>Amazon Ramdisk Image (ARI)</primary>
        </indexterm>

      <glossdef>
        <para>Both a VM container format and disk format. Supported by Image
        Service.</para>
      </glossdef>
    </glossentry>

    <glossentry>
      <glossterm>Anvil</glossterm>
      <indexterm class="singular">
          <primary>Anvil</primary>
        </indexterm>

      <glossdef>
        <para>A project that ports the shell script-based project named
        DevStack to Python.</para>
      </glossdef>
    </glossentry>

    <glossentry>
      <glossterm>Apache</glossterm>
      <indexterm class="singular">
          <primary>Apache</primary>
        </indexterm>

      <glossdef>
        <para>The Apache Software Foundation supports the Apache community of
        open-source software projects. These projects provide software
        products for the public good.</para>
      </glossdef>
    </glossentry>

    <glossentry>
      <glossterm>Apache License 2.0</glossterm>
      <indexterm class="singular">
          <primary>Apache License 2.0</primary>
        </indexterm>

      <glossdef>
        <para>All OpenStack core projects are provided under the terms of the
        Apache License 2.0 license.</para>
      </glossdef>
    </glossentry>

    <glossentry>
      <glossterm>Apache Web Server</glossterm>
      <indexterm class="singular">
          <primary>Apache Web Server</primary>
        </indexterm>

      <glossdef>
        <para>The most common web server software currently used on the
        Internet.</para>
      </glossdef>
    </glossentry>

    <glossentry>
      <glossterm>API</glossterm>

      <glossdef>
        <para>Application programming interface.</para>
      </glossdef>
    </glossentry>

    <glossentry>
      <glossterm>API endpoint</glossterm>
      <indexterm class="singular">
          <primary>endpoints</primary>

          <secondary>API endpoint</secondary>
        </indexterm>
      <indexterm class="singular">
          <primary>API (application programming interface)</primary>

          <secondary>API endpoint</secondary>
        </indexterm>

      <glossdef>
        <para>The daemon, worker, or service that a client communicates with
        to access an API. API endpoints can provide any number of services,
        such as authentication, sales data, performance metrics, Compute VM
        commands, census data, and so on.</para>
      </glossdef>
    </glossentry>

    <glossentry>
      <glossterm>API extension</glossterm>
      <indexterm class="singular">
          <primary>API (application programming interface)</primary>

          <secondary>API extension</secondary>
        </indexterm>

      <glossdef>
        <para>Custom modules that extend some OpenStack core APIs.</para>
      </glossdef>
    </glossentry>

    <glossentry>
      <glossterm>API extension plug-in</glossterm>
      <indexterm class="singular">
          <primary>API (application programming interface)</primary>

          <secondary>API extension plug-in</secondary>
        </indexterm>

      <glossdef>
        <para>Alternative term for a Networking plug-in or Networking API
        extension.</para>
      </glossdef>
    </glossentry>

    <glossentry>
      <glossterm>API key</glossterm>
      <indexterm class="singular">
          <primary>API (application programming interface)</primary>

          <secondary>API key</secondary>
        </indexterm>

      <glossdef>
        <para>Alternative term for an API token.</para>
      </glossdef>
    </glossentry>

    <glossentry>
      <glossterm>API server</glossterm>
      <indexterm class="singular">
          <primary>API (application programming interface)</primary>

          <secondary>API server</secondary>
        </indexterm>

      <glossdef>
        <para>Any node running a daemon or worker that provides an API
        endpoint.</para>
      </glossdef>
    </glossentry>

    <glossentry>
      <glossterm>API token</glossterm>
      <indexterm class="singular">
          <primary>API (application programming interface)</primary>

          <secondary>API token</secondary>
        </indexterm>

      <glossdef>
        <para>Passed to API requests and used by OpenStack to verify that the
        client is authorized to run the requested operation.</para>
      </glossdef>
    </glossentry>

    <glossentry>
      <glossterm>API version</glossterm>
      <indexterm class="singular">
          <primary>API (application programming interface)</primary>

          <secondary>API version</secondary>
        </indexterm>

      <glossdef>
        <para>In OpenStack, the API version for a project is part of the URL.
        For example, <filename>example.com/nova/v1/foobar</filename>.</para>
      </glossdef>
    </glossentry>

    <glossentry>
      <glossterm>applet</glossterm>
      <indexterm class="singular">
          <primary>applet</primary>
        </indexterm>

      <glossdef>
        <para>A Java program that can be embedded into a web page.</para>
      </glossdef>
    </glossentry>

    <glossentry>
      <glossterm>Application Programming Interface (API)</glossterm>

      <glossdef>
        <para>A collection of specifications used to access a service,
        application, or program. Includes service calls, required parameters
        for each call, and the expected return values.</para>
      </glossdef>
    </glossentry>

    <glossentry>
      <glossterm>application server</glossterm>
      <indexterm class="singular">
          <primary>servers</primary>

          <secondary>application servers</secondary>
        </indexterm>
      <indexterm class="singular">
          <primary>application server</primary>
        </indexterm>

      <glossdef>
        <para>A piece of software that makes available another piece of
        software over a network.</para>
      </glossdef>
    </glossentry>

    <glossentry>
      <glossterm>Application Service Provider (ASP)</glossterm>
      <indexterm class="singular">
          <primary>Application Service Provider (ASP)</primary>
        </indexterm>

      <glossdef>
        <para>
          Companies that rent specialized applications that help
          businesses and organizations provide additional services
          with lower cost.
        </para>
      </glossdef>
    </glossentry>

    <glossentry>
      <glossterm>Address Resolution Protocol (ARP)</glossterm>
      <indexterm class="singular">
        <primary>Address Resolution Protocol (ARP)</primary>
      </indexterm>

      <glossdef>
        <para>
          The protocol by which layer-3 IP addresses are resolved into
          layer-2 link local addresses.
        </para>
      </glossdef>
    </glossentry>

    <glossentry>
      <glossterm>arptables</glossterm>
      <indexterm class="singular">
          <primary>arptables</primary>
        </indexterm>

      <glossdef>
        <para>Tool used for maintaining Address Resolution Protocol packet
        filter rules in the Linux kernel firewall modules. Used along with
        iptables, ebtables, and ip6tables in Compute to provide firewall
        services for VMs.</para>
      </glossdef>
    </glossentry>

    <glossentry>
      <glossterm>associate</glossterm>
      <indexterm class="singular">
          <primary>associate, definition of</primary>
        </indexterm>

      <glossdef>
        <para>The process associating a Compute floating IP address with a
        fixed IP address.</para>
      </glossdef>
    </glossentry>

    <glossentry>
      <glossterm>Asynchronous JavaScript and XML (AJAX)</glossterm>
      <indexterm
          class="singular">
          <primary>Asynchronous JavaScript and XML (AJAX)</primary>
        </indexterm>

      <glossdef>
        <para>A group of interrelated web development techniques used on the
        client-side to create asynchronous web applications. Used extensively
        in horizon.</para>
      </glossdef>
    </glossentry>

    <glossentry>
      <glossterm>ATA over Ethernet (AoE)</glossterm>
      <indexterm class="singular">
          <primary>ATA over Ethernet (AoE)</primary>
        </indexterm>

      <glossdef>
        <para>A disk storage protocol tunneled within Ethernet.</para>
      </glossdef>
    </glossentry>

    <glossentry>
      <glossterm>attach</glossterm>
      <indexterm class="singular">
          <primary>attach, definition of</primary>
        </indexterm>

      <glossdef>
        <para>The process of connecting a VIF or vNIC to a L2 network in
        Networking. In the context of Compute, this process connects a storage
        volume to an instance.</para>
      </glossdef>
    </glossentry>

    <glossentry>
      <glossterm>attachment (network)</glossterm>
      <indexterm class="singular">
          <primary>attachment (network)</primary>
        </indexterm>

      <glossdef>
        <para>Association of an interface ID to a logical port. Plugs an
        interface into a port.</para>
      </glossdef>
    </glossentry>

    <glossentry>
      <glossterm>auditing</glossterm>
      <indexterm class="singular">
          <primary>auditing</primary>
        </indexterm>

      <glossdef>
        <para>Provided in Compute through the system usage data
        facility.</para>
      </glossdef>
    </glossentry>

    <glossentry>
      <glossterm>auditor</glossterm>
      <indexterm class="singular">
          <primary>auditor</primary>
        </indexterm>

      <glossdef>
        <para>A worker process that verifies the integrity of Object Storage
        objects, containers, and accounts. Auditors is the collective term for
        the Object Storage account auditor, container auditor, and object
        auditor.</para>
      </glossdef>
    </glossentry>

    <glossentry>
      <glossterm>Austin</glossterm>
      <indexterm class="singular">
          <primary>Austin</primary>
        </indexterm>

      <glossdef>
        <para>The code name for the initial release of
        OpenStack. The first design summit took place in
        Austin, Texas, US.</para>
      </glossdef>
    </glossentry>

    <glossentry>
      <glossterm>auth node</glossterm>
      <indexterm class="singular">
          <primary>auth node</primary>
        </indexterm>

      <glossdef>
        <para>Alternative term for an Object Storage authorization
        node.</para>
      </glossdef>
    </glossentry>

    <glossentry>
      <glossterm>authentication</glossterm>
      <indexterm class="singular">
          <primary>authentication</primary>
        </indexterm>

      <glossdef>
        <para>The process that confirms that the user, process, or client is
        really who they say they are through private key, secret token,
        password, fingerprint, or similar method.</para>
      </glossdef>
    </glossentry>

    <glossentry>
      <glossterm>authentication token</glossterm>
      <indexterm class="singular">
          <primary>authentication tokens</primary>
        </indexterm>

      <glossdef>
        <para>A string of text provided to the client after authentication.
        Must be provided by the user or process in subsequent requests to the
        API endpoint.</para>
      </glossdef>
    </glossentry>

    <glossentry>
      <glossterm>AuthN</glossterm>
      <indexterm class="singular">
          <primary>AuthN</primary>
        </indexterm>

      <glossdef>
        <para>The Identity Service component that provides authentication
        services.</para>
      </glossdef>
    </glossentry>

    <glossentry>
      <glossterm>authorization</glossterm>
      <indexterm class="singular">
          <primary>authorization</primary>
        </indexterm>

      <glossdef>
        <para>The act of verifying that a user, process, or client is
        authorized to perform an action.</para>
      </glossdef>
    </glossentry>

    <glossentry>
      <glossterm>authorization node</glossterm>
      <indexterm class="singular">
          <primary>authorization node</primary>
        </indexterm>

      <glossdef>
        <para>An Object Storage node that provides authorization
        services.</para>
      </glossdef>
    </glossentry>

    <glossentry>
      <glossterm>AuthZ</glossterm>
      <indexterm class="singular">
          <primary>AuthZ</primary>
        </indexterm>

      <glossdef>
        <para>The Identity Service component that provides high-level
        authorization services.</para>
      </glossdef>
    </glossentry>

    <glossentry>
      <glossterm>Auto ACK</glossterm>
      <indexterm class="singular">
          <primary>Auto ACK</primary>
        </indexterm>

      <glossdef>
        <para>Configuration setting within RabbitMQ that enables or disables
        message acknowledgment. Enabled by default.</para>
      </glossdef>
    </glossentry>

    <glossentry>
      <glossterm>auto declare</glossterm>
      <indexterm class="singular">
          <primary>auto declare</primary>
        </indexterm>

      <glossdef>
        <para>A Compute RabbitMQ setting that determines whether a message
        exchange is automatically created when the program starts.</para>
      </glossdef>
    </glossentry>

    <glossentry>
      <glossterm>availability zone</glossterm>
      <indexterm class="singular">
          <primary>availability zone</primary>
        </indexterm>

      <glossdef>
        <para>An Amazon EC2 concept of an isolated area that is used for fault
        tolerance. Do not confuse with an OpenStack Compute zone or
        cell.</para>
      </glossdef>
    </glossentry>

    <glossentry>
      <glossterm>AWS</glossterm>
      <indexterm class="singular">
          <primary>AWS (Amazon Web Services)</primary>
        </indexterm>

      <glossdef>
        <para>Amazon Web Services.</para>
      </glossdef>
    </glossentry>

    <glossentry>
      <glossterm>AWS CloudFormation template</glossterm>
      <indexterm class="singular">
          <primary>AWS CloudFormation template</primary>
        </indexterm>

      <glossdef>
        <para>
          AWS CloudFormation allows AWS users to create and manage a
          collection of related resources. The Orchestration module
          supports a CloudFormation-compatible format (CFN).
        </para>
      </glossdef>
    </glossentry>
  </glossdiv>

  <!-- .B. -->

  <glossdiv>
    <title>B</title>

    <glossentry>
      <glossterm>back end</glossterm>
      <indexterm class="singular">
          <primary>back-end interactions</primary>

          <secondary>definition of</secondary>
        </indexterm>

      <glossdef>
        <para>Interactions and processes that are obfuscated from the user,
        such as Compute volume mount, data transmission to an iSCSI target by
        a daemon, or Object Storage object integrity checks.</para>
      </glossdef>
    </glossentry>

    <glossentry>
      <glossterm>back-end catalog</glossterm>
      <indexterm class="singular">
          <primary>back-end interactions</primary>

          <secondary>catalog</secondary>
        </indexterm>

      <glossdef>
        <para>The storage method used by the Identity Service catalog service
        to store and retrieve information about API endpoints that are
        available to the client. Examples include a SQL database, LDAP
        database, or KVS back end.</para>
      </glossdef>
    </glossentry>

    <glossentry>
      <glossterm>back-end store</glossterm>
      <indexterm class="singular">
          <primary>back-end interactions</primary>

          <secondary>store</secondary>
        </indexterm>

      <glossdef>
        <para>The persistent data store used to save and retrieve information
        for a service, such as lists of Object Storage objects, current state
        of guest VMs, lists of user names, and so on. Also, the method that the
        Image Service uses to get and store VM images. Options include Object
        Storage, local file system, S3, and HTTP.</para>
      </glossdef>
    </glossentry>

    <glossentry>
      <glossterm>bandwidth</glossterm>
      <indexterm class="singular">
          <primary>bandwidth</primary>

          <secondary>definition of</secondary>
        </indexterm>

      <glossdef>
        <para>The amount of available data used by communication resources,
        such as the Internet. Represents the amount of data that is used to
        download things or the amount of data available to download.</para>
      </glossdef>
    </glossentry>

    <glossentry>
      <glossterm>bare</glossterm>
      <indexterm class="singular">
          <primary>bare, definition of</primary>
        </indexterm>

      <glossdef>
        <para>An Image Service container format that indicates that no
        container exists for the VM image.</para>
      </glossdef>
    </glossentry>

    <glossentry>
      <glossterm>base image</glossterm>
      <indexterm class="singular">
          <primary>base image</primary>
        </indexterm>

      <glossdef>
        <para>An OpenStack-provided image.</para>
      </glossdef>
    </glossentry>

    <glossentry>
      <glossterm>Bell-LaPadula model</glossterm>
      <indexterm class="singular">
          <primary>Bell-LaPadula model</primary>
        </indexterm>

      <glossdef>
        <para>A security model that focuses on data confidentiality
        and controlled access to classified information.
        This model divide the entities into subjects and objects.
        The clearance of a subject is compared to the classification of the
        object to determine if the subject is authorized for the specific access mode.
        The clearance or classification scheme is expressed in terms of a lattice.</para>
      </glossdef>
    </glossentry>

    <glossentry>
      <glossterm>Bexar</glossterm>
      <indexterm class="singular">
          <primary>Bexar</primary>
        </indexterm>

      <glossdef>
        <para>A grouped release of projects related to
        OpenStack that came out in February of 2011. It
        included only Compute (nova) and Object Storage (swift).</para>
        <para>Bexar is the code name for the second release of
        OpenStack. The design summit took place in
        San Antonio, Texas, US, which is the county seat for Bexar county.</para>
      </glossdef>
    </glossentry>

    <glossentry>
      <glossterm>binary</glossterm>
      <indexterm class="singular">
          <primary>binary</primary>

          <secondary>definition of</secondary>
        </indexterm>

      <glossdef>
        <para>Information that consists solely of ones and zeroes, which is
        the language of computers.</para>
      </glossdef>
    </glossentry>

    <glossentry>
      <glossterm>bit</glossterm>
      <indexterm class="singular">
          <primary>bits, definition of</primary>
        </indexterm>

      <glossdef>
        <para>A bit is a single digit number that is in base of 2 (either a
        zero or one). Bandwidth usage is measured in bits per second.</para>
      </glossdef>
    </glossentry>

    <glossentry>
      <glossterm>bits per second (BPS)</glossterm>
      <indexterm class="singular">
          <primary>bits per second (BPS)</primary>
        </indexterm>

      <glossdef>
        <para>The universal measurement of how quickly data is transferred
        from place to place.</para>
      </glossdef>
    </glossentry>

    <glossentry>
      <glossterm>block device</glossterm>
      <indexterm class="singular">
          <primary>block device</primary>
        </indexterm>

      <glossdef>
        <para>A device that moves data in the form of blocks. These device
        nodes interface the devices, such as hard disks, CD-ROM drives, flash
        drives, and other addressable regions of memory.</para>
      </glossdef>
    </glossentry>

    <glossentry>
      <glossterm>block migration</glossterm>
      <indexterm class="singular">
          <primary>block migration</primary>
        </indexterm>

      <glossdef>
        <para>A method of VM live migration used by KVM to evacuate instances
        from one host to another with very little downtime during a
        user-initiated switchover. Does not require shared storage. Supported
        by Compute.</para>
      </glossdef>
    </glossentry>

    <glossentry>
      <glossterm>Block Storage</glossterm>
      <indexterm class="singular">
          <primary>Block Storage</primary>
        </indexterm>

      <glossdef>
        <para>The OpenStack core project that enables management of volumes,
        volume snapshots, and volume types. The project name of Block Storage
        is cinder.</para>
      </glossdef>
    </glossentry>

    <glossentry>
      <glossterm>Block Storage API</glossterm>
      <indexterm class="singular">
          <primary>Block Storage API</primary>
        </indexterm>

        <glossdef>
          <para>An API on a separate endpoint for attaching,
          detaching, and creating block storage for compute
          VMs.</para>
        </glossdef>
    </glossentry>

    <glossentry>
      <glossterm>BMC</glossterm>
      <indexterm class="singular">
          <primary>BMC (Baseboard Management Controller)</primary>
        </indexterm>

      <glossdef>
        <para>Baseboard Management Controller. The intelligence in the IPMI
        architecture, which is a specialized micro-controller that is embedded
        on the motherboard of a computer and acts as a server. Manages the
        interface between system management software and platform
        hardware.</para>
      </glossdef>
    </glossentry>

    <glossentry>
      <glossterm>bootable disk image</glossterm>
      <indexterm class="singular">
          <primary>bootable disk image</primary>
        </indexterm>

      <glossdef>
        <para>A type of VM image that exists as a single, bootable
        file.</para>
      </glossdef>
    </glossentry>

    <glossentry>
      <glossterm>Bootstrap Protocol (BOOTP)</glossterm>
      <indexterm class="singular">
          <primary>Bootstrap Protocol (BOOTP)</primary>
      </indexterm>

      <glossdef>
        <para>A network protocol used by a network client to obtain an IP
        address from a configuration server. Provided in Compute through the
        dnsmasq daemon when using either the FlatDHCP manager or VLAN manager
        network manager.</para>
      </glossdef>
    </glossentry>

    <glossentry>
      <glossterm>Border Gateway Protocol (BGP)</glossterm>
      <indexterm class="singular">
        <primary>Border Gateway Protocol (BGP)</primary>
      </indexterm>
      <glossdef>
        <para>
          The Border Gateway Protocol is a dynamic routing protocol
          that connects autonomous systems.  Considered the
          backbone of the Internet, this protocol connects disparate
          networks to form a larger network.</para>
      </glossdef>
    </glossentry>

    <glossentry>
      <glossterm>browser</glossterm>
      <indexterm class="singular">
          <primary>browsers, definition of</primary>
        </indexterm>

      <glossdef>
        <para>Any client software that enables a computer or device to access
        the Internet.</para>
      </glossdef>
    </glossentry>

    <glossentry>
      <glossterm>builder file</glossterm>
      <indexterm class="singular">
          <primary>builder files</primary>
        </indexterm>

      <glossdef>
        <para>Contains configuration information that Object Storage uses to
        reconfigure a ring or to re-create it from scratch after a serious
        failure.</para>
      </glossdef>
    </glossentry>

    <glossentry>
      <glossterm>bursting</glossterm>
      <indexterm class="singular">
          <primary>bursting</primary>
        </indexterm>

      <glossdef>
        <para>
          The practice of utilizing a secondary environment to
          elastically build instances on-demand when the primary
          environment is resource constrained.
        </para>
      </glossdef>
    </glossentry>

    <glossentry>
      <glossterm>button class</glossterm>
      <indexterm class="singular">
          <primary>button classes</primary>
        </indexterm>

      <glossdef>
        <para>A group of related button types within horizon. Buttons to
        start, stop, and suspend VMs are in one class. Buttons to associate
        and disassociate floating IP addresses are in another class, and so
        on.</para>
      </glossdef>
    </glossentry>

    <glossentry>
      <glossterm>byte</glossterm>
      <indexterm class="singular">
          <primary>bytes, definition of</primary>
        </indexterm>

      <glossdef>
        <para>Set of bits that make up a single character; there are usually 8
        bits to a byte.</para>
      </glossdef>
    </glossentry>
  </glossdiv>

  <!-- .C. -->

  <glossdiv>
    <title>C</title>

    <glossentry>
      <glossterm>CA</glossterm>
      <indexterm class="singular">
          <primary>CA (Certificate/Certification Authority)</primary>
        </indexterm>

      <glossdef>
        <para>Certificate Authority or Certification Authority. In
        cryptography, an entity that issues digital certificates. The digital
        certificate certifies the ownership of a public key by the named
        subject of the certificate. This enables others (relying parties) to
        rely upon signatures or assertions made by the private key that
        corresponds to the certified public key. In this model of trust
        relationships, a CA is a trusted third party for both the subject
        (owner) of the certificate and the party relying upon the certificate.
        CAs are characteristic of many public key infrastructure (PKI)
        schemes.</para>
      </glossdef>
    </glossentry>

    <glossentry>
      <glossterm>cache pruner</glossterm>
      <indexterm class="singular">
          <primary>cache pruners</primary>
        </indexterm>

      <glossdef>
        <para>A program that keeps the Image Service VM image cache at or
        below its configured maximum size.</para>
      </glossdef>
    </glossentry>

    <glossentry>
      <glossterm>Cactus</glossterm>
      <indexterm class="singular">
          <primary>Cactus</primary>
        </indexterm>

      <glossdef>
        <para>An OpenStack grouped release of projects that came out in the
        spring of 2011. It included Compute (nova), Object Storage (swift),
        and the Image Service (glance).</para>
        <para>Cactus is a city in Texas, US and is the code name for
        the third release of OpenStack. When OpenStack releases went
        from three to six months long, the code name of the release
        changed to match a geography nearest the previous
        summit.</para>
      </glossdef>
    </glossentry>
    <glossentry>
      <glossterm>CADF</glossterm>
      <glossdef>
        <para>
          Cloud Auditing Data Federation (CADF) is a
          specification for audit event data. CADF is
          supported by OpenStack Identity.
        </para>
      </glossdef>
    </glossentry>

    <glossentry>
      <glossterm>CALL</glossterm>
      <indexterm class="singular">
          <primary>CALL</primary>
        </indexterm>

      <glossdef>
        <para>One of the RPC primitives used by the OpenStack message queue
        software. Sends a message and waits for a response.</para>
      </glossdef>
    </glossentry>

    <glossentry>
      <glossterm>capability</glossterm>
      <indexterm class="singular">
          <primary>capability</primary>

          <secondary>definition of</secondary>
        </indexterm>

      <glossdef>
        <para>Defines resources for a cell, including CPU, storage, and
        networking. Can apply to the specific services within a cell or a
        whole cell.</para>
      </glossdef>
    </glossentry>

    <glossentry>
      <glossterm>capacity cache</glossterm>
      <indexterm class="singular">
          <primary>capacity cache</primary>
        </indexterm>

      <glossdef>
        <para>A Compute back-end database table that contains the current
        workload, amount of free RAM, and number of VMs running on each host.
        Used to determine on which VM a host starts.</para>
      </glossdef>
    </glossentry>

    <glossentry>
      <glossterm>capacity updater</glossterm>
      <indexterm class="singular">
          <primary>capacity updater</primary>
        </indexterm>

      <glossdef>
        <para>A notification driver that monitors VM instances and updates the
        capacity cache as needed.</para>
      </glossdef>
    </glossentry>

    <glossentry>
      <glossterm>CAST</glossterm>
      <indexterm class="singular">
          <primary>CAST (RPC primitive)</primary>
        </indexterm>

      <glossdef>
        <para>One of the RPC primitives used by the OpenStack message queue
        software. Sends a message and does not wait for a response.</para>
      </glossdef>
    </glossentry>

    <glossentry>
      <glossterm>catalog</glossterm>
      <indexterm class="singular">
          <primary>catalog</primary>
        </indexterm>

      <glossdef>
        <para>A list of API endpoints that are available to a user after
        authentication with the Identity Service.</para>
      </glossdef>
    </glossentry>

    <glossentry>
      <glossterm>catalog service</glossterm>
      <indexterm class="singular">
          <primary>catalog service</primary>
        </indexterm>

      <glossdef>
        <para>An Identity Service that lists API endpoints that are available
        to a user after authentication with the Identity Service.</para>
      </glossdef>
    </glossentry>

    <glossentry>
      <glossterm>ceilometer</glossterm>
      <indexterm class="singular">
          <primary>ceilometer</primary>
        </indexterm>

      <glossdef>
        <para>The project name for the Telemetry service, which is an
        integrated project that provides metering and measuring facilities for
        OpenStack.</para>
      </glossdef>
    </glossentry>

    <glossentry>
      <glossterm>cell</glossterm>
      <indexterm class="singular">
          <primary>cells</primary>

          <secondary>definition of</secondary>
        </indexterm>

      <glossdef>
        <para>Provides logical partitioning of Compute resources in a child
        and parent relationship. Requests are passed from parent cells to
        child cells if the parent cannot provide the requested
        resource.</para>
      </glossdef>
    </glossentry>

    <glossentry>
      <glossterm>cell forwarding</glossterm>
      <indexterm class="singular">
          <primary>cells</primary>

          <secondary>cell forwarding</secondary>
        </indexterm>

      <glossdef>
        <para>A Compute option that enables parent cells to pass resource
        requests to child cells if the parent cannot provide the requested
        resource.</para>
      </glossdef>
    </glossentry>

    <glossentry>
      <glossterm>cell manager</glossterm>
      <indexterm class="singular">
          <primary>cells</primary>

          <secondary>cell managers</secondary>
        </indexterm>

      <glossdef>
        <para>The Compute component that contains a list of the current
        capabilities of each host within the cell and routes requests as
        appropriate.</para>
      </glossdef>
    </glossentry>

    <glossentry>
      <glossterm>CentOS</glossterm>
      <indexterm class="singular">
          <primary>CentOS</primary>
        </indexterm>

      <glossdef>
        <para>A Linux distribution that is compatible with OpenStack.</para>
      </glossdef>
    </glossentry>

    <glossentry>
      <glossterm>Ceph</glossterm>
      <indexterm class="singular">
          <primary>Ceph</primary>
        </indexterm>

      <glossdef>
        <para>Massively scalable distributed storage system that consists of
        an object store, block store, and POSIX-compatible distributed file
        system. Compatible with OpenStack.</para>
      </glossdef>
    </glossentry>

    <glossentry>
      <glossterm>CephFS</glossterm>
      <indexterm class="singular">
          <primary>CephFS</primary>
        </indexterm>

      <glossdef>
        <para>The POSIX-compliant file system provided by Ceph.</para>
      </glossdef>
    </glossentry>

    <glossentry>
      <glossterm>certificate authority</glossterm>
      <indexterm class="singular">
          <primary>certificate authority (Compute)</primary>
        </indexterm>

      <glossdef>
        <para>A simple certificate authority provided by Compute for cloudpipe
        VPNs and VM image decryption.</para>
      </glossdef>
    </glossentry>

    <glossentry>
      <glossterm>Challenge-Handshake Authentication Protocol (CHAP)</glossterm>
      <indexterm
          class="singular">
          <primary>Challenge-Handshake Authentication Protocol
          (CHAP)</primary>
        </indexterm>

      <glossdef>
        <para>An iSCSI authentication method supported by Compute.</para>
      </glossdef>
    </glossentry>

    <glossentry>
      <glossterm>chance scheduler</glossterm>
      <indexterm class="singular">
          <primary>chance scheduler</primary>
        </indexterm>

      <glossdef>
        <para>A scheduling method used by Compute that randomly chooses an
        available host from the pool.</para>
      </glossdef>
    </glossentry>

    <glossentry>
      <glossterm>changes since</glossterm>
      <indexterm class="singular">
          <primary>changes since</primary>
        </indexterm>

      <glossdef>
        <para>A Compute API parameter that downloads changes to the requested
        item since your last request, instead of downloading a new, fresh set
        of data and comparing it against the old data.</para>
      </glossdef>
    </glossentry>

    <glossentry>
      <glossterm>Chef</glossterm>
      <indexterm class="singular">
          <primary>Chef</primary>
        </indexterm>

      <glossdef>
        <para>An operating system configuration management tool supporting
        OpenStack deployments.</para>
      </glossdef>
    </glossentry>

    <glossentry>
      <glossterm>child cell</glossterm>
      <indexterm class="singular">
          <primary>cells</primary>

          <secondary>child cells</secondary>
        </indexterm>
      <indexterm class="singular">
          <primary>child cells</primary>
        </indexterm>

      <glossdef>
        <para>If a requested resource such as CPU time, disk storage, or
        memory is not available in the parent cell, the request is forwarded
        to its associated child cells. If the child cell can fulfill the
        request, it does. Otherwise, it attempts to pass the request to any of
        its children.</para>
      </glossdef>
    </glossentry>

    <glossentry>
      <glossterm>cinder</glossterm>
      <indexterm class="singular">
          <primary>cinder</primary>
        </indexterm>

      <glossdef>
        <para>A core OpenStack project that provides block storage services
        for VMs.</para>
      </glossdef>
    </glossentry>

    <glossentry>
      <glossterm>CirrOS</glossterm>
      <indexterm class="singular">
          <primary>CirrOS</primary>
        </indexterm>

        <glossdef>
          <para>A minimal Linux distribution designed for use as a test
             image on clouds such as OpenStack.</para>
        </glossdef>
    </glossentry>

    <glossentry>
      <glossterm>Cisco neutron plug-in</glossterm>
      <indexterm class="singular">
          <primary>Cisco neutron plug-in</primary>
        </indexterm>

      <glossdef>
        <para>A Networking plug-in for Cisco devices and technologies,
        including UCS and Nexus.</para>
      </glossdef>
    </glossentry>

    <glossentry>
      <glossterm>cloud architect</glossterm>
      <indexterm class="singular">
          <primary>cloud architect</primary>
        </indexterm>

      <glossdef>
        <para>A person who plans, designs, and oversees the creation of
        clouds.</para>
      </glossdef>
    </glossentry>

    <glossentry>
      <glossterm>cloud computing</glossterm>
      <indexterm class="singular">
          <primary>cloud computing</primary>

          <secondary>definition of</secondary>
        </indexterm>

      <glossdef>
        <para>A model that enables access to a shared pool of configurable
        computing resources, such as networks, servers, storage, applications,
        and services, that can be rapidly provisioned and released with
        minimal management effort or service provider interaction.</para>
      </glossdef>
    </glossentry>

    <glossentry>
      <glossterm>cloud controller</glossterm>
      <indexterm class="singular">
          <primary>cloud computing</primary>

          <secondary>cloud controllers</secondary>
        </indexterm>

      <glossdef>
        <para>Collection of Compute components that represent the global state
        of the cloud; talks to services, such as Identity Service
        authentication, Object Storage, and node/storage workers through a
        queue.</para>
      </glossdef>
    </glossentry>

    <glossentry>
      <glossterm>cloud controller node</glossterm>
      <indexterm class="singular">
          <primary>cloud computing</primary>

          <secondary>cloud controller nodes</secondary>
        </indexterm>

      <glossdef>
        <para>A node that runs network, volume, API, scheduler, and image
        services. Each service may be broken out into separate nodes for
        scalability or availability.</para>
      </glossdef>
    </glossentry>

    <glossentry>
      <glossterm>Cloud Data Management Interface (CDMI)</glossterm>
      <indexterm
          class="singular">
          <primary>Cloud Data Management Interface (CDMI)</primary>
        </indexterm>

      <glossdef>
        <para>SINA standard that defines a RESTful API for managing objects in
        the cloud, currently unsupported in OpenStack.</para>
      </glossdef>
    </glossentry>

    <glossentry>
      <glossterm>Cloud Infrastructure Management Interface (CIMI)</glossterm>
      <indexterm
          class="singular">
          <primary>Cloud Infrastructure Management Interface (CIMI)</primary>
        </indexterm>

      <glossdef>
        <para>An in-progress specification for cloud management. Currently
        unsupported in OpenStack.</para>
      </glossdef>
    </glossentry>

    <glossentry>
      <glossterm>cloud-init</glossterm>
      <indexterm class="singular">
          <primary>cloud-init</primary>
        </indexterm>

      <glossdef>
        <para>A package commonly installed in VM images that performs
        initialization of an instance after boot using information that it
        retrieves from the metadata service, such as the SSH public key and
        user data.</para>
      </glossdef>
    </glossentry>

    <glossentry>
      <glossterm>cloudadmin</glossterm>
      <indexterm class="singular">
          <primary>cloudadmin</primary>
        </indexterm>

      <glossdef>
        <para>One of the default roles in the Compute RBAC system. Grants
        complete system access.</para>
      </glossdef>
    </glossentry>

    <glossentry>
      <glossterm>Cloudbase-Init</glossterm>
      <indexterm class="singular">
          <primary>Cloudbase-Init</primary>
          <see>cloud-init</see>
        </indexterm>

      <glossdef>
          <para>A Windows port of cloud-init.</para>
      </glossdef>
    </glossentry>

    <glossentry>
      <glossterm>cloudpipe</glossterm>
      <indexterm class="singular">
          <primary>cloudpipe</primary>

          <secondary>definition of</secondary>
        </indexterm>

      <glossdef>
        <para>A compute service that creates VPNs on a per-project
        basis.</para>
      </glossdef>
    </glossentry>

    <glossentry>
      <glossterm>cloudpipe image</glossterm>
      <indexterm class="singular">
          <primary>cloudpipe</primary>

          <secondary>cloudpipe image</secondary>
        </indexterm>

      <glossdef>
        <para>A pre-made VM image that serves as a cloudpipe server.
        Essentially, OpenVPN running on Linux.</para>
      </glossdef>
    </glossentry>

    <glossentry>
      <glossterm>CMDB</glossterm>
      <indexterm class="singular">
          <primary>CMDB (Configuration Management Database)</primary>
        </indexterm>

      <glossdef>
        <para>Configuration Management Database.</para>
      </glossdef>
    </glossentry>

    <glossentry>
      <glossterm>command filter</glossterm>
      <indexterm class="singular">
          <primary>command filters</primary>
        </indexterm>

      <glossdef>
        <para>Lists allowed commands within the Compute rootwrap
        facility.</para>
      </glossdef>
    </glossentry>

    <glossentry>
      <glossterm>community project</glossterm>
      <indexterm class="singular">
          <primary>community projects</primary>
        </indexterm>

      <glossdef>
        <para>A project that is not officially endorsed by the OpenStack
        Foundation. If the project is successful enough, it might be elevated
        to an incubated project and then to a core project, or it might be
        merged with the main code trunk.</para>
      </glossdef>
    </glossentry>

    <glossentry>
      <glossterm>compression</glossterm>
      <indexterm class="singular">
          <primary>compression</primary>
        </indexterm>

      <glossdef>
        <para>Reducing the size of files by special encoding, the file can be
        decompressed again to its original content. OpenStack supports
        compression at the Linux file system level but does not support
        compression for things such as Object Storage objects or Image Service
        VM images.</para>
      </glossdef>
    </glossentry>

    <glossentry>
      <glossterm>Compute</glossterm>
      <indexterm class="singular">
          <primary>Compute</primary>

          <secondary>definition of</secondary>
        </indexterm>

      <glossdef>
        <para>The OpenStack core project that provides compute services. The
        project name of Compute service is nova.</para>
      </glossdef>
    </glossentry>

    <glossentry>
      <glossterm>Compute API</glossterm>
      <indexterm class="singular">
          <primary>Compute</primary>

          <secondary>Compute API</secondary>
        </indexterm>

      <glossdef>
        <para>The <systemitem class="service">nova-api</systemitem> daemon
        provides access to nova services. Can communicate with other APIs,
        such as the Amazon EC2 API.</para>
      </glossdef>
    </glossentry>

    <glossentry>
      <glossterm>compute controller</glossterm>
      <indexterm class="singular">
          <primary>Compute</primary>

          <secondary>compute controller</secondary>
        </indexterm>

      <glossdef>
        <para>The Compute component that chooses suitable hosts on which to
        start VM instances.</para>
      </glossdef>
    </glossentry>

    <glossentry>
      <glossterm>compute host</glossterm>
      <indexterm class="singular">
          <primary>Compute</primary>

          <secondary>compute host</secondary>
        </indexterm>

      <glossdef>
        <para>Physical host dedicated to running compute nodes.</para>
      </glossdef>
    </glossentry>

    <glossentry>
      <glossterm>compute node</glossterm>
      <indexterm class="singular">
          <primary>compute nodes</primary>

          <secondary>definition of</secondary>
        </indexterm>

      <glossdef>
        <para>A node that runs the <systemitem
        class="service">nova-compute</systemitem> daemon that manages VM
        instances that <phrase role="keep-together">provide</phrase> a wide
        range of services, such as web applications and analytics.</para>
      </glossdef>
    </glossentry>

    <glossentry>
      <glossterm>Compute service</glossterm>
      <indexterm class="singular">
          <primary>Compute</primary>

          <secondary>Compute service</secondary>
        </indexterm>

      <glossdef>
        <para>Name for the Compute component that manages VMs.</para>
      </glossdef>
    </glossentry>

    <glossentry>
      <glossterm>compute worker</glossterm>
      <indexterm class="singular">
          <primary>Compute</primary>

          <secondary>compute worker</secondary>
        </indexterm>

      <glossdef>
        <para>The Compute component that runs on each compute node and manages
        the VM instance life cycle, including run, reboot, terminate,
        attach/detach volumes, and so on. Provided by the <systemitem
        class="service">nova-compute</systemitem> daemon.</para>
      </glossdef>
    </glossentry>

    <glossentry>
      <glossterm>concatenated object</glossterm>
      <indexterm class="singular">
          <primary>objects</primary>

          <secondary>concatenated objects</secondary>
        </indexterm>
      <indexterm class="singular">
          <primary>concatenated objects</primary>
        </indexterm>

      <glossdef>
        <para>A set of segment objects that Object Storage combines and sends
        to the client.</para>
      </glossdef>
    </glossentry>

    <glossentry>
      <glossterm>conductor</glossterm>
      <indexterm class="singular">
          <primary>conductors</primary>
        </indexterm>

      <glossdef>
        <para>In Compute, conductor is the process that proxies database
        requests from the compute process. Using conductor improves security
        because compute nodes do not need direct access to the
        database.</para>
      </glossdef>
    </glossentry>

    <glossentry>
      <glossterm>consistency window</glossterm>
      <indexterm class="singular">
          <primary>consistency window</primary>
        </indexterm>

      <glossdef>
        <para>The amount of time it takes for a new Object Storage object to
        become accessible to all clients.</para>
      </glossdef>
    </glossentry>

    <glossentry>
      <glossterm>console log</glossterm>
      <indexterm class="singular">
          <primary>console logs</primary>
        </indexterm>

      <glossdef>
        <para>Contains the output from a Linux VM console in Compute.</para>
      </glossdef>
    </glossentry>

    <glossentry>
      <glossterm>container</glossterm>
      <indexterm class="singular">
          <primary>containers</primary>

          <secondary>definition of</secondary>
        </indexterm>

      <glossdef>
        <para>Organizes and stores objects in Object Storage. Similar to the
        concept of a Linux directory but cannot be nested. Alternative term
        for an Image Service container format.</para>
      </glossdef>
    </glossentry>

    <glossentry>
      <glossterm>container auditor</glossterm>
      <indexterm class="singular">
          <primary>containers</primary>

          <secondary>container auditors</secondary>
        </indexterm>

      <glossdef>
        <para>Checks for missing replicas or incorrect objects in specified
        Object Storage containers through queries to the SQLite back-end
        database.</para>
      </glossdef>
    </glossentry>

    <glossentry>
      <glossterm>container database</glossterm>
      <indexterm class="singular">
          <primary>containers</primary>

          <secondary>container databases</secondary>
        </indexterm>

      <glossdef>
        <para>A SQLite database that stores Object Storage containers and
        container metadata. The container server accesses this
        database.</para>
      </glossdef>
    </glossentry>

    <glossentry>
      <glossterm>container format</glossterm>
      <indexterm class="singular">
          <primary>containers</primary>

          <secondary>container format</secondary>
        </indexterm>

      <glossdef>
        <para>A wrapper used by the Image Service that contains a VM image and
        its associated metadata, such as machine state, OS disk size, and so
        on.</para>
      </glossdef>
    </glossentry>

    <glossentry>
      <glossterm>container server</glossterm>
      <indexterm class="singular">
          <primary>containers</primary>

          <secondary>container servers</secondary>
        </indexterm>

      <glossdef>
        <para>An Object Storage server that manages containers.</para>
      </glossdef>
    </glossentry>

    <glossentry>
      <glossterm>container service</glossterm>
      <indexterm class="singular">
          <primary>containers</primary>

          <secondary>container service</secondary>
        </indexterm>

      <glossdef>
        <para>The Object Storage component that provides container services,
        such as create, delete, list, and so on.</para>
      </glossdef>
    </glossentry>

    <glossentry>
      <glossterm>content delivery network (CDN)</glossterm>
      <indexterm class="singular">
          <primary>content delivery network (CDN)</primary>
        </indexterm>

      <glossdef>
        <para>
          A content delivery network is a specialized network that is
          used to distribute content to clients, typically located
          close to the client for increased performance.
        </para>
      </glossdef>
    </glossentry>


    <glossentry>
      <glossterm>controller node</glossterm>
      <indexterm class="singular">
          <primary>controller nodes</primary>

          <see>under cloud computing</see>
        </indexterm>

      <glossdef>
        <para>Alternative term for a cloud controller node.</para>
      </glossdef>
    </glossentry>

    <glossentry>
      <glossterm>core API</glossterm>
      <indexterm class="singular">
          <primary>core API</primary>
        </indexterm>

      <glossdef>
        <para>Depending on context, the core API is either the OpenStack API
        or the main API of a specific core project, such as Compute,
        Networking, Image Service, and so on.</para>
      </glossdef>
    </glossentry>

    <glossentry>
      <glossterm>core project</glossterm>
      <indexterm class="singular">
          <primary>core project</primary>
        </indexterm>

      <glossdef>
        <para>An official OpenStack project. Currently consists of Compute
        (nova), Object Storage (swift), Image Service (glance), Identity
        (keystone), Dashboard (horizon), Networking (neutron), and Block
        Storage (cinder). The Telemetry module (ceilometer) and Orchestration
        module (heat) are integrated projects as of the Havana release. In the
        Icehouse release, the Database module (trove) gains integrated project
        status.</para>
      </glossdef>
    </glossentry>

    <glossentry>
      <glossterm>cost</glossterm>
      <indexterm class="singular">
          <primary>cost</primary>
        </indexterm>

      <glossdef>
        <para>Under the Compute distributed scheduler, this is calculated by
        looking at the capabilities of each host relative to the flavor of the
        VM instance being requested.</para>
      </glossdef>
    </glossentry>

    <glossentry>
      <glossterm>credentials</glossterm>
      <indexterm class="singular">
          <primary>credentials</primary>
        </indexterm>

      <glossdef>
        <para>Data that is only known to or accessible by a user and used to
        verify that the user is who he says he is. Credentials are presented
        to the server during authentication. Examples include a password,
        secret key, digital certificate, and fingerprint.</para>
      </glossdef>
    </glossentry>

    <glossentry>
      <glossterm>Crowbar</glossterm>
      <indexterm class="singular">
          <primary>Crowbar</primary>
        </indexterm>

      <glossdef>
        <para>An open source community project by Dell that aims to provide
        all necessary services to quickly deploy clouds.</para>
      </glossdef>
    </glossentry>

    <glossentry>
      <glossterm>current workload</glossterm>
      <indexterm class="singular">
          <primary>current workload</primary>
        </indexterm>

      <glossdef>
        <para>An element of the Compute capacity cache that is calculated
        based on the number of build, snapshot, migrate, and resize operations
        currently in progress on a given host.</para>
      </glossdef>
    </glossentry>

    <glossentry>
      <glossterm>customer</glossterm>
      <indexterm class="singular">
          <primary>customers</primary>

          <see>tenants</see>
        </indexterm>

      <glossdef>
        <para>Alternative term for tenant.</para>
      </glossdef>
    </glossentry>

    <glossentry>
      <glossterm>customization module</glossterm>
      <indexterm class="singular">
          <primary>customization module</primary>
        </indexterm>

      <glossdef>
        <para>A user-created Python module that is loaded by horizon to change
        the look and feel of the dashboard.</para>
      </glossdef>
    </glossentry>
  </glossdiv>

  <!-- .D. -->

  <glossdiv>
    <title>D</title>

    <glossentry>
      <glossterm>daemon</glossterm>
      <indexterm class="singular">
          <primary>daemons</primary>

          <secondary>definition of</secondary>
        </indexterm>

      <glossdef>
        <para>A process that runs in the background and waits for requests.
        May or may not listen on a TCP or UDP port. Do not confuse with a
        worker.</para>
      </glossdef>
    </glossentry>

    <glossentry>
      <glossterm>DAC</glossterm>
      <indexterm class="singular">
          <primary>DAC (discretionary access control)</primary>
        </indexterm>

      <glossdef>
        <para>Discretionary access control. Governs the ability of subjects to
        access objects, while enabling users to make policy decisions and
        assign security attributes. The traditional UNIX system of users,
        groups, and read-write-execute permissions is an example of
        DAC.</para>
      </glossdef>
    </glossentry>

    <glossentry>
      <glossterm>dashboard</glossterm>
      <indexterm class="singular">
          <primary>dashboard</primary>
        </indexterm>

      <glossdef>
        <para>The web-based management interface for OpenStack. An alternative
        name for horizon.</para>
      </glossdef>
    </glossentry>

    <glossentry>
      <glossterm>data encryption</glossterm>
      <indexterm class="singular">
          <primary>data</primary>

          <secondary>data encryption</secondary>
        </indexterm>

      <glossdef>
        <para>Both Image Service and Compute support encrypted virtual machine
        (VM) images (but not instances). In-transit data encryption is
        supported in OpenStack using technologies such as HTTPS, SSL, TLS, and
        SSH. Object Storage does not support object encryption at the
        application level but may support storage that uses disk <phrase
        role="keep-together">encryption</phrase>.</para>
      </glossdef>
    </glossentry>

    <glossentry>
      <glossterm>database ID</glossterm>
      <indexterm class="singular">
          <primary>databases</primary>

          <secondary>database ID</secondary>
        </indexterm>

      <glossdef>
        <para>A unique ID given to each replica of an Object Storage
        database.</para>
      </glossdef>
    </glossentry>

    <glossentry>
      <glossterm>database replicator</glossterm>
      <indexterm class="singular">
          <primary>databases</primary>

          <secondary>database replicators</secondary>
        </indexterm>

      <glossdef>
        <para>An Object Storage component that copies changes in the account,
        container, and object databases to other nodes.</para>
      </glossdef>
    </glossentry>

    <glossentry>
      <glossterm>Database Service</glossterm>
      <indexterm class="singular">
          <primary>Database Service</primary>
        </indexterm>

      <glossdef>
        <para>
          An integrated project that provide scalable and reliable
          Cloud Database-as-a-Service functionality for both
          relational and non-relational database engines. The project
          name of Database Service is trove.
        </para>
      </glossdef>
    </glossentry>

    <glossentry>
      <glossterm>deallocate</glossterm>
      <indexterm class="singular">
          <primary>deallocate, definition of</primary>
        </indexterm>

      <glossdef>
        <para>The process of removing the association between a floating IP
        address and a fixed IP address. Once this association is removed, the
        floating IP returns to the address pool.</para>
      </glossdef>
    </glossentry>

    <glossentry>
      <glossterm>Debian</glossterm>
      <indexterm class="singular">
          <primary>Debian</primary>
        </indexterm>

      <glossdef>
        <para>A Linux distribution that is compatible with OpenStack.</para>
      </glossdef>
    </glossentry>

    <glossentry>
      <glossterm>deduplication</glossterm>
      <indexterm class="singular">
          <primary>deduplication</primary>
        </indexterm>

      <glossdef>
        <para>The process of finding duplicate data at the disk block, file,
        and/or object level to minimize storage use&mdash;currently unsupported
        within OpenStack.</para>
      </glossdef>
    </glossentry>

    <glossentry>
      <glossterm>default panel</glossterm>
      <indexterm class="singular">
          <primary>default panels</primary>
        </indexterm>

      <glossdef>
        <para>The default panel that is displayed when a user accesses the
        horizon dashboard.</para>
      </glossdef>
    </glossentry>

    <glossentry>
      <glossterm>default tenant</glossterm>
      <indexterm class="singular">
          <primary>default tenants</primary>
        </indexterm>

      <glossdef>
        <para>New users are assigned to this tenant if no tenant is specified
        when a user is created.</para>
      </glossdef>
    </glossentry>

    <glossentry>
      <glossterm>default token</glossterm>
      <indexterm class="singular">
          <primary>default tokens</primary>
        </indexterm>

      <glossdef>
        <para>An Identity Service token that is not associated with a specific
        tenant and is exchanged for a scoped token.</para>
      </glossdef>
    </glossentry>

    <glossentry>
      <glossterm>delayed delete</glossterm>
      <indexterm class="singular">
          <primary>delayed delete</primary>
        </indexterm>

      <glossdef>
        <para>An option within Image Service so that an image is deleted after
        a predefined number of seconds instead of immediately.</para>
      </glossdef>
    </glossentry>

    <glossentry>
      <glossterm>delivery mode</glossterm>
      <indexterm class="singular">
          <primary>delivery mode</primary>
        </indexterm>

      <glossdef>
        <para>Setting for the Compute RabbitMQ message delivery mode; can be
        set to either transient or persistent.</para>
      </glossdef>
    </glossentry>

    <glossentry>
      <glossterm>denial of service (DoS)</glossterm>
      <indexterm class="singular">
        <primary>denial of service (DoS)</primary>
      </indexterm>

      <glossdef>
        <para>
          Denial of service (DoS) is a short form for
          denial-of-service attack. This is a malicious attempt to
          prevent legitimate users from using a service.
        </para>
      </glossdef>
    </glossentry>
    <glossentry>
      <glossterm>deprecated auth</glossterm>
      <indexterm class="singular">
          <primary>deprecated auth</primary>
        </indexterm>

      <glossdef>
        <para>An option within Compute that enables administrators to create
        and manage users through the <literal>nova-manage</literal> command as
        opposed to using the Identity Service.</para>
      </glossdef>
    </glossentry>

    <glossentry>
      <glossterm>Desktop-as-a-Service</glossterm>
      <indexterm class="singular">
          <primary>Desktop-as-a-Service</primary>
        </indexterm>

      <glossdef>
        <para>
          A platform that provides a suite of desktop environments
          that users may log in to receive a desktop experience from
          any location. This may provide general use, development, or
          even homogeneous testing environments.
        </para>
      </glossdef>
    </glossentry>

    <glossentry>
      <glossterm>developer</glossterm>
      <indexterm class="singular">
          <primary>developer</primary>
        </indexterm>

      <glossdef>
        <para>One of the default roles in the Compute RBAC system and the
        default role assigned to a new user.</para>
      </glossdef>
    </glossentry>

    <glossentry>
      <glossterm>device ID</glossterm>
      <indexterm class="singular">
          <primary>device ID</primary>
        </indexterm>

      <glossdef>
        <para>Maps Object Storage partitions to physical storage
        devices.</para>
      </glossdef>
    </glossentry>

    <glossentry>
      <glossterm>device weight</glossterm>
      <indexterm class="singular">
          <primary>device weight</primary>
        </indexterm>

      <glossdef>
        <para>Distributes partitions proportionately across Object Storage
        devices based on the storage capacity of each device.</para>
      </glossdef>
    </glossentry>

    <glossentry>
      <glossterm>DevStack</glossterm>
      <indexterm class="singular">
          <primary>DevStack</primary>

          <secondary>definition of</secondary>
        </indexterm>

      <glossdef>
        <para>Community project that uses shell scripts to quickly build
        complete OpenStack development environments.</para>
      </glossdef>
    </glossentry>

    <glossentry>
      <glossterm>DHCP</glossterm>
      <indexterm class="singular">
          <primary>DHCP (Dynamic Host Configuration Protocol)</primary>

          <secondary>basics of</secondary>
        </indexterm>

      <glossdef>
        <para>Dynamic Host Configuration Protocol. A network protocol that
        configures devices that are connected to a network so that they can
        communicate on that network by using the Internet Protocol (IP). The
        protocol is implemented in a client-server model where DHCP clients
        request configuration data, such as an IP address, a default route,
        and one or more DNS server addresses from a DHCP server.</para>
      </glossdef>
    </glossentry>

    <glossentry>
      <glossterm>DHCP agent</glossterm>
      <indexterm class="singular">
        <primary>DHCP agent</primary>
        </indexterm>

      <glossdef>
        <para>OpenStack Networking agent that provides DHCP services
          for virtual networks.</para>
      </glossdef>
    </glossentry>

    <glossentry>
      <glossterm>Diablo</glossterm>
      <indexterm class="singular">
          <primary>Diablo</primary>
        </indexterm>

      <glossdef>
        <para>A grouped release of projects related to OpenStack that came out
        in the fall of 2011, the fourth release of OpenStack. It included
        Compute (nova 2011.3), Object Storage (swift 1.4.3), and the Image
        Service (glance).</para>
        <para>Diablo is the code name for the fourth release of
        OpenStack. The design summit took place in
        in the Bay Area near Santa Clara,
        California, US and Diablo is a nearby city.</para>
      </glossdef>
    </glossentry>

    <glossentry>
      <glossterm>direct consumer</glossterm>
      <indexterm class="singular">
          <primary>direct consumers</primary>
        </indexterm>

      <glossdef>
        <para>An element of the Compute RabbitMQ that comes to life when a RPC
        call is executed. It connects to a direct exchange through a unique
        exclusive queue, sends the message, and terminates.</para>
      </glossdef>
    </glossentry>

    <glossentry>
      <glossterm>direct exchange</glossterm>
      <indexterm class="singular">
          <primary>direct exchanges</primary>
        </indexterm>

      <glossdef>
        <para>A routing table that is created within the Compute RabbitMQ
        during RPC calls; one is created for each RPC call that is
        invoked.</para>
      </glossdef>
    </glossentry>

    <glossentry>
      <glossterm>direct publisher</glossterm>
      <indexterm class="singular">
          <primary>direct publishers</primary>
        </indexterm>

      <glossdef>
        <para>Element of RabbitMQ that provides a response to an incoming MQ
        message.</para>
      </glossdef>
    </glossentry>

    <glossentry>
      <glossterm>disassociate</glossterm>
      <indexterm class="singular">
          <primary>disassociate</primary>
        </indexterm>

      <glossdef>
        <para>The process of removing the association between a floating IP
        address and fixed IP and thus returning the floating IP address to the
        address pool.</para>
      </glossdef>
    </glossentry>

    <glossentry>
      <glossterm>disk encryption</glossterm>
      <indexterm class="singular">
          <primary>disk encryption</primary>
        </indexterm>

      <glossdef>
        <para>The ability to encrypt data at the file system, disk partition,
        or whole-disk level. Supported within Compute VMs.</para>
      </glossdef>
    </glossentry>

    <glossentry>
      <glossterm>disk format</glossterm>
      <indexterm class="singular">
          <primary>disk format</primary>
        </indexterm>

      <glossdef>
        <para>The underlying format that a disk image for a VM is stored as
        within the Image Service back-end store. For example, AMI, ISO, QCOW2,
        VMDK, and so on.</para>
      </glossdef>
    </glossentry>

    <glossentry>
      <glossterm>dispersion</glossterm>
      <indexterm class="singular">
          <primary>dispersion</primary>
        </indexterm>

      <glossdef>
        <para>In Object Storage, tools to test and ensure dispersion of
        objects and containers to ensure fault tolerance.</para>
      </glossdef>
    </glossentry>

    <glossentry>
      <glossterm>distributed virtual router (DVR)</glossterm>
      <indexterm class="singular">
        <primary>distributed virtual router (DVR)</primary>
      </indexterm>

      <glossdef>
        <para>Mechanism for highly-available multi-host routing when using
          OpenStack Networking (neutron).</para>
      </glossdef>
    </glossentry>

    <glossentry>
      <glossterm>Django</glossterm>
      <indexterm class="singular">
          <primary>Django</primary>
        </indexterm>

      <glossdef>
        <para>A web framework used extensively in <phrase
        role="keep-together">horizon</phrase>.</para>
      </glossdef>
    </glossentry>

    <glossentry>
      <glossterm>DNS</glossterm>
      <indexterm class="singular">
          <primary>DNS (Domain Name Server, Service or System)</primary>

          <secondary>definitions of</secondary>
        </indexterm>

      <glossdef>
        <para>Domain Name Server. A hierarchical and distributed naming system
        for computers, services, and resources connected to the Internet or a
        private network. Associates a human-friendly names to IP
        addresses.</para>
      </glossdef>
    </glossentry>

    <glossentry>
      <glossterm>DNS record</glossterm>
      <indexterm class="singular">
          <primary>DNS (Domain Name Server, Service or System)</primary>

          <secondary>DNS records</secondary>
        </indexterm>

      <glossdef>
        <para>A record that specifies information about a particular domain
        and belongs to the domain.</para>
      </glossdef>
    </glossentry>

    <glossentry>
      <glossterm>dnsmasq</glossterm>
      <indexterm class="singular">
          <primary>dnsmasq</primary>
        </indexterm>

      <glossdef>
        <para>Daemon that provides DNS, DHCP, BOOTP, and TFTP services, used
        by the Compute VLAN manager and FlatDHCP manager.</para>
      </glossdef>
    </glossentry>

    <glossentry>
      <glossterm>domain</glossterm>
      <indexterm class="singular">
          <primary>domain, definition of</primary>
        </indexterm>

      <glossdef>
        <para>Separates a website from other sites. Often, the domain name has
        two or more parts that are separated by dots. For example, yahoo.com,
        usa.gov, harvard.edu, or mail.yahoo.com.</para>

        <para>A domain is an entity or container of all DNS-related
        information containing one or more records.</para>
      </glossdef>
    </glossentry>

    <glossentry>
      <glossterm>Domain Name Service (DNS)</glossterm>

      <glossdef>
        <para>In Compute, the support that enables associating DNS entries
        with floating IP addresses, nodes, or cells so that hostnames are
        consistent across reboots.</para>
      </glossdef>
    </glossentry>

    <glossentry>
      <glossterm>Domain Name System (DNS)</glossterm>

      <glossdef>
        <para>A system by which Internet domain name-to-address and
        address-to-name resolutions are determined.</para>

        <para>DNS helps navigate the Internet by translating the IP address
        into an address that is easier to remember For example, translating
        111.111.111.1 into www.yahoo.com.</para>

        <para>All domains and their components, such as mail servers, utilize
        DNS to resolve to the appropriate locations. DNS servers are usually
        set up in a master-slave relationship such that failure of the master
        invokes the slave. DNS servers might also be clustered or replicated
        such that changes made to one DNS server are automatically propagated
        to other active servers.</para>
      </glossdef>
    </glossentry>

    <glossentry>
      <glossterm>download</glossterm>
      <indexterm class="singular">
          <primary>download, definition of</primary>
        </indexterm>

      <glossdef>
        <para>The transfer of data, usually in the form of files, from one
        computer to another.</para>
      </glossdef>
    </glossentry>

    <glossentry>
      <glossterm>DRTM</glossterm>
      <indexterm class="singular">
          <primary>DRTM (dynamic root of trust measurement)</primary>
        </indexterm>

      <glossdef>
        <para>Dynamic root of trust measurement.</para>
      </glossdef>
    </glossentry>

    <glossentry>
      <glossterm>durable exchange</glossterm>
      <indexterm class="singular">
          <primary>durable exchange</primary>
        </indexterm>

      <glossdef>
        <para>The Compute RabbitMQ message exchange that remains active when
        the server restarts.</para>
      </glossdef>
    </glossentry>

    <glossentry>
      <glossterm>durable queue</glossterm>
      <indexterm class="singular">
          <primary>durable queue</primary>
        </indexterm>

      <glossdef>
        <para>A Compute RabbitMQ message queue that remains active when the
        server restarts.</para>
      </glossdef>
    </glossentry>

    <glossentry>
      <glossterm>Dynamic Host Configuration Protocol (DHCP)</glossterm>

      <glossdef>
        <para>A method to automatically configure networking for a host at
        boot time. Provided by both Networking and Compute.</para>
      </glossdef>
    </glossentry>

    <glossentry>
      <glossterm>Dynamic HyperText Markup Language (DHTML)</glossterm>
      <indexterm
          class="singular">
          <primary>DHTML (Dynamic HyperText Markup Language)</primary>
        </indexterm>

      <glossdef>
        <para>Pages that use HTML, JavaScript, and Cascading Style Sheets to
        enable users to interact with a web page or show simple
        animation.</para>
      </glossdef>
    </glossentry>
  </glossdiv>

  <!-- .E. -->

  <glossdiv>
    <title>E</title>

    <glossentry>
      <glossterm>east-west traffic</glossterm>
      <indexterm class="singular">
        <primary>east-west traffic</primary>
      </indexterm>

      <glossdef>
        <para>
          Network traffic between servers in the same cloud or data center.
          See also north-south traffic.
        </para>
      </glossdef>
    </glossentry>
    <glossentry>
      <glossterm>EBS boot volume</glossterm>
      <indexterm class="singular">
          <primary>EBS boot volume</primary>
        </indexterm>

      <glossdef>
        <para>An Amazon EBS storage volume that contains a bootable VM image,
        currently unsupported in OpenStack.</para>
      </glossdef>
    </glossentry>

    <glossentry>
      <glossterm>ebtables</glossterm>
      <indexterm class="singular">
          <primary>ebtables</primary>
        </indexterm>

      <glossdef>
        <para>Used in Compute along with arptables, iptables, and ip6tables to
        create firewalls and to ensure isolation of network
        communications.</para>
      </glossdef>
    </glossentry>

    <glossentry>
      <glossterm>EC2</glossterm>

      <glossdef>
        <para>The Amazon commercial compute product, similar to
        Compute.</para>
      </glossdef>
    </glossentry>

    <glossentry>
      <glossterm>EC2 access key</glossterm>
      <indexterm class="singular">
          <primary>EC2</primary>

          <secondary>EC2 access key</secondary>
        </indexterm>

      <glossdef>
        <para>Used along with an EC2 secret key to access the Compute EC2
        API.</para>
      </glossdef>
    </glossentry>

    <glossentry>
      <glossterm>EC2 API</glossterm>
      <indexterm class="singular">
          <primary>EC2</primary>

          <secondary>EC2 API</secondary>
        </indexterm>

      <glossdef>
        <para>OpenStack supports accessing the Amazon EC2 API through
        Compute.</para>
      </glossdef>
    </glossentry>

    <glossentry>
      <glossterm>EC2 Compatibility API</glossterm>
      <indexterm class="singular">
          <primary>EC2</primary>

          <secondary>EC2 compatibility API</secondary>
        </indexterm>

      <glossdef>
        <para>A Compute component that enables OpenStack to communicate with
        Amazon EC2.</para>
      </glossdef>
    </glossentry>

    <glossentry>
      <glossterm>EC2 secret key</glossterm>
      <indexterm class="singular">
          <primary>EC2</primary>

          <secondary>EC2 secret key</secondary>
        </indexterm>

      <glossdef>
        <para>Used along with an EC2 access key when communicating with the
        Compute EC2 API; used to digitally sign each request.</para>
      </glossdef>
    </glossentry>

    <glossentry>
      <glossterm>Elastic Block Storage (EBS)</glossterm>
      <indexterm class="singular">
          <primary>Elastic Block Storage (EBS)</primary>
        </indexterm>

      <glossdef>
        <para>The Amazon commercial block storage product.</para>
      </glossdef>
    </glossentry>

    <glossentry>
      <glossterm>encryption</glossterm>
      <indexterm class="singular">
          <primary>encryption, definition of</primary>
        </indexterm>

      <glossdef>
        <para>OpenStack supports encryption technologies such as HTTPS, SSH,
        SSL, TLS, digital certificates, and data encryption.</para>
      </glossdef>
    </glossentry>

    <glossentry>
      <glossterm>endpoint</glossterm>

      <glossdef>
        <para>See API endpoint.</para>
      </glossdef>
    </glossentry>

    <glossentry>
      <glossterm>endpoint registry</glossterm>
      <indexterm class="singular">
          <primary>endpoints</primary>

          <secondary>endpoint registry</secondary>
        </indexterm>

      <glossdef>
        <para>Alternative term for an Identity Service catalog.</para>
      </glossdef>
    </glossentry>

    <glossentry>
      <glossterm>encapsulation</glossterm>
      <indexterm class="singular">
        <primary>encapsulation</primary>
      </indexterm>

      <glossdef>
        <para>
          The practice of placing one packet type within another for
          the purposes of abstracting or securing data. Examples
          include GRE, MPLS, or IPsec.
        </para>
      </glossdef>
    </glossentry>

    <glossentry>
      <glossterm>endpoint template</glossterm>
      <indexterm class="singular">
          <primary>endpoints</primary>

          <secondary>endpoint templates</secondary>
        </indexterm>

      <glossdef>
        <para>A list of URL and port number endpoints that indicate where a
        service, such as Object Storage, Compute, Identity, and so on, can be
        accessed.</para>
      </glossdef>
    </glossentry>

    <glossentry>
      <glossterm>entity</glossterm>
      <indexterm class="singular">
          <primary>entity, definition of</primary>
        </indexterm>

      <glossdef>
        <para>Any piece of hardware or software that wants to connect to the
        network services provided by Networking, the network connectivity
        service. An entity can make use of Networking by implementing a
        VIF.</para>
      </glossdef>
    </glossentry>

    <glossentry>
      <glossterm>ephemeral image</glossterm>
      <indexterm class="singular">
          <primary>ephemeral images</primary>
        </indexterm>

      <glossdef>
        <para>A VM image that does not save changes made to its volumes and
        reverts them to their original state after the instance is
        terminated.</para>
      </glossdef>
    </glossentry>

    <glossentry>
      <glossterm>ephemeral volume</glossterm>
      <indexterm class="singular">
          <primary>ephemeral volume</primary>
        </indexterm>

      <glossdef>
        <para>Volume that does not save the changes made to it and reverts to
        its original state when the current user relinquishes control.</para>
      </glossdef>
    </glossentry>

    <glossentry>
      <glossterm>Essex</glossterm>
      <indexterm class="singular">
          <primary>Essex</primary>
        </indexterm>

      <glossdef>
        <para>A grouped release of projects related to OpenStack that came out
        in April 2012, the fifth release of OpenStack. It included Compute
        (nova 2012.1), Object Storage (swift 1.4.8), Image (glance), Identity
        (keystone), and Dashboard (horizon).</para>
        <para>Essex is the code name for the fifth release of
        OpenStack. The design summit took place in
        Boston, Massachusetts, US and Essex is a nearby city.</para>
      </glossdef>
    </glossentry>

    <glossentry>
      <glossterm>ESX</glossterm>
      <indexterm class="singular">
          <primary>ESX hypervisor</primary>
        </indexterm>

      <glossdef>
        <para>An OpenStack-supported hypervisor.</para>
      </glossdef>
    </glossentry>

    <glossentry>
      <glossterm>ESXi</glossterm>
      <indexterm class="singular">
          <primary>ESXi hypervisor</primary>
        </indexterm>

      <glossdef>
        <para>An OpenStack-supported hypervisor.</para>
      </glossdef>
    </glossentry>

    <glossentry>
      <glossterm>ebtables</glossterm>
      <indexterm class="singular">
          <primary>ebtables</primary>
        </indexterm>

      <glossdef>
        <para>Filtering tool for a Linux bridging firewall, enabling filtering
        of network traffic passing through a Linux bridge. Used to restrict
        communications between hosts and/or nodes in OpenStack Compute along
        with iptables, arptables, and ip6tables.</para>
      </glossdef>
    </glossentry>

    <glossentry>
      <glossterm>ETag</glossterm>
      <indexterm class="singular">
          <primary>ETag</primary>
        </indexterm>

      <glossdef>
        <para>MD5 hash of an object within Object Storage, used to ensure data
        integrity.</para>
      </glossdef>
    </glossentry>

    <glossentry>
      <glossterm>euca2ools</glossterm>
      <indexterm class="singular">
          <primary>euca2ools</primary>
        </indexterm>

      <glossdef>
        <para>A collection of command-line tools for administering VMs; most
        are compatible with OpenStack.</para>
      </glossdef>
    </glossentry>

    <glossentry>
      <glossterm>Eucalyptus Kernel Image (EKI)</glossterm>
      <indexterm class="singular">
          <primary>Eucalyptus Kernel Image (EKI)</primary>
        </indexterm>

      <glossdef>
        <para>Used along with an ERI to create an EMI.</para>
      </glossdef>
    </glossentry>

    <glossentry>
      <glossterm>Eucalyptus Machine Image (EMI)</glossterm>
      <indexterm class="singular">
          <primary>Eucalyptus Machine Image (EMI)</primary>
        </indexterm>

      <glossdef>
        <para>VM image container format supported by Image Service.</para>
      </glossdef>
    </glossentry>

    <glossentry>
      <glossterm>Eucalyptus Ramdisk Image (ERI)</glossterm>
      <indexterm class="singular">
          <primary>Eucalyptus Ramdisk Image (ERI)</primary>
        </indexterm>

      <glossdef>
        <para>Used along with an EKI to create an EMI.</para>
      </glossdef>
    </glossentry>

    <glossentry>
      <glossterm>evacuate</glossterm>
      <indexterm class="singular">
          <primary>evacuation, definition of</primary>
        </indexterm>

      <glossdef>
        <para>The process of migrating one or all virtual machine (VM)
        instances from one host to another, compatible with both shared
        storage live migration and block migration.</para>
      </glossdef>
    </glossentry>

    <glossentry>
      <glossterm>exchange</glossterm>
      <indexterm class="singular">
          <primary>exchange</primary>
        </indexterm>

      <glossdef>
        <para>Alternative term for a RabbitMQ message exchange.</para>
      </glossdef>
    </glossentry>

    <glossentry>
      <glossterm>exchange type</glossterm>
      <indexterm class="singular">
          <primary>exchange types</primary>
        </indexterm>

      <glossdef>
        <para>A routing algorithm in the Compute RabbitMQ.</para>
      </glossdef>
    </glossentry>

    <glossentry>
      <glossterm>exclusive queue</glossterm>
      <indexterm class="singular">
          <primary>queues</primary>

          <secondary>exclusive queues</secondary>
        </indexterm>
      <indexterm class="singular">
          <primary>exclusive queues</primary>
        </indexterm>

      <glossdef>
        <para>Connected to by a direct consumer in RabbitMQ&mdash;Compute, the
        message can be consumed only by the current connection.</para>
      </glossdef>
    </glossentry>

    <glossentry>
      <glossterm>extended attributes (xattrs)</glossterm>
      <indexterm class="singular">
          <primary>extended attributes (xattrs)</primary>
        </indexterm>

      <glossdef>
        <para>File system option that enables storage of additional
        information beyond owner, group, permissions, modification time, and
        so on. The underlying Object Storage file system must support extended
        attributes.</para>
      </glossdef>
    </glossentry>

    <glossentry>
      <glossterm>extension</glossterm>
      <indexterm class="singular">
          <primary>extensions</primary>

          <secondary>definition of</secondary>
        </indexterm>

      <glossdef>
        <para>Alternative term for an API extension or plug-in. In the context
        of Identity Service, this is a call that is specific to the
        implementation, such as adding support for OpenID.</para>
      </glossdef>
    </glossentry>

    <glossentry>
      <glossterm>external network</glossterm>
      <indexterm class="singular">
          <primary>external network, definition of</primary>
        </indexterm>

      <glossdef>
        <para>A network segment typically used for instance Internet
        access.</para>
      </glossdef>
    </glossentry>

    <glossentry>
      <glossterm>extra specs</glossterm>
      <indexterm class="singular">
          <primary>extra specs, definition of</primary>
        </indexterm>

      <glossdef>
        <para>Specifies additional requirements when Compute determines where
        to start a new instance. Examples include a minimum amount of network
        bandwidth or a GPU.</para>
      </glossdef>
    </glossentry>
  </glossdiv>

  <!-- .F. -->

  <glossdiv>
    <title>F</title>

    <glossentry>
      <glossterm>FakeLDAP</glossterm>
      <indexterm class="singular">
          <primary>FakeLDAP</primary>
        </indexterm>

      <glossdef>
        <para>An easy method to create a local LDAP directory for testing
        Identity Service and Compute. Requires Redis.</para>
      </glossdef>
    </glossentry>

    <glossentry>
      <glossterm>fan-out exchange</glossterm>
      <indexterm class="singular">
          <primary>fan-out exchange</primary>
        </indexterm>

      <glossdef>
        <para>Within RabbitMQ and Compute, it is the messaging interface that
        is used by the scheduler service to receive capability messages from
        the compute, volume, and network nodes.</para>
      </glossdef>
    </glossentry>

    <glossentry>
      <glossterm>Fedora</glossterm>
      <indexterm class="singular">
          <primary>Fedora</primary>
        </indexterm>

      <glossdef>
        <para>A Linux distribution compatible with OpenStack.</para>
      </glossdef>
    </glossentry>

    <glossentry>
      <glossterm>Fibre Channel</glossterm>
      <indexterm class="singular">
          <primary>Fibre Channel</primary>
        </indexterm>

      <glossdef>
        <para>Storage protocol similar in concept to TCP/IP; encapsulates SCSI
        commands and data.</para>
      </glossdef>
    </glossentry>

    <glossentry>
      <glossterm>Fibre Channel over Ethernet (FCoE)</glossterm>
      <indexterm class="singular">
          <primary>Fibre Channel over Ethernet (FCoE)</primary>
        </indexterm>

      <glossdef>
        <para>The fibre channel protocol tunneled within Ethernet.</para>
      </glossdef>
    </glossentry>

    <glossentry>
      <glossterm>fill-first scheduler</glossterm>
      <indexterm class="singular">
          <primary>fill-first scheduler</primary>
        </indexterm>

      <glossdef>
        <para>The Compute scheduling method that attempts to fill a host with
        VMs rather than starting new VMs on a variety of hosts.</para>
      </glossdef>
    </glossentry>

    <glossentry>
      <glossterm>filter</glossterm>
      <indexterm class="singular">
          <primary>filtering</primary>

          <secondary>definition of</secondary>
        </indexterm>

      <glossdef>
        <para>The step in the Compute scheduling process when hosts that
        cannot run VMs are eliminated and not chosen.</para>
      </glossdef>
    </glossentry>

    <glossentry>
      <glossterm>firewall</glossterm>
      <indexterm class="singular">
          <primary>firewalls</primary>
        </indexterm>

      <glossdef>
        <para>Used to restrict communications between hosts and/or nodes,
        implemented in Compute using iptables, arptables, ip6tables, and
        etables.</para>
      </glossdef>
    </glossentry>

    <glossentry>
      <glossterm>Firewall-as-a-Service (FWaaS)</glossterm>
      <indexterm class="singular">
          <primary>Firewall-as-a-Service (FWaaS)</primary>
        </indexterm>

      <glossdef>
        <para>A Networking extension that provides perimeter firewall
        functionality.</para>
      </glossdef>
    </glossentry>

    <glossentry>
      <glossterm>fixed IP address</glossterm>
      <indexterm class="singular">
          <primary>IP addresses</primary>

          <secondary>fixed</secondary>
        </indexterm>
      <indexterm class="singular">
          <primary>fixed IP addresses</primary>
        </indexterm>

      <glossdef>
        <para>An IP address that is associated with the same instance each
        time that instance boots, is generally not accessible to end users or
        the public Internet, and is used for management of the
        instance.</para>
      </glossdef>
    </glossentry>

    <glossentry>
      <glossterm>Flat Manager</glossterm>
      <indexterm class="singular">
          <primary>Flat Manager</primary>
        </indexterm>

      <glossdef>
        <para>The Compute component that gives IP addresses to authorized
        nodes and assumes DHCP, DNS, and routing configuration and services
        are provided by something else.</para>
      </glossdef>
    </glossentry>

    <glossentry>
      <glossterm>flat mode injection</glossterm>
      <indexterm class="singular">
          <primary>flat mode injection</primary>
        </indexterm>

      <glossdef>
        <para>A Compute networking method where the OS network configuration
        information is injected into the VM image before the instance
        starts.</para>
      </glossdef>
    </glossentry>

    <glossentry>
      <glossterm>flat network</glossterm>
      <indexterm class="singular">
          <primary>flat network</primary>
        </indexterm>

      <glossdef>
        <para>The Network Controller provides virtual networks to enable
        compute servers to interact with each other and with the public
        network. All machines must have a public and private network
        interface. A flat network is a private network interface, which is
        controlled by the <literal>flat_interface</literal> option with flat
        managers.</para>
      </glossdef>
    </glossentry>

    <glossentry>
      <glossterm>FlatDHCP Manager</glossterm>
      <indexterm class="singular">
          <primary>FlatDHCP Manager</primary>
        </indexterm>

      <glossdef>
        <para>The Compute component that provides dnsmasq (DHCP, DNS, BOOTP,
        TFTP) and radvd (routing) services.</para>
      </glossdef>
    </glossentry>

    <glossentry>
      <glossterm>flavor</glossterm>
      <indexterm class="singular">
          <primary>flavor</primary>
        </indexterm>

      <glossdef>
        <para>Alternative term for a VM instance type.</para>
      </glossdef>
    </glossentry>

    <glossentry>
      <glossterm>flavor ID</glossterm>
      <indexterm class="singular">
          <primary>flavor ID</primary>
        </indexterm>

      <glossdef>
        <para>UUID for each Compute or Image Service VM flavor or instance
        type.</para>
      </glossdef>
    </glossentry>

    <glossentry>
      <glossterm>floating IP address</glossterm>
      <indexterm class="singular">
          <primary>IP addresses</primary>

          <secondary>floating</secondary>
        </indexterm>
      <indexterm class="singular">
          <primary>floating IP address</primary>
        </indexterm>

      <glossdef>
        <para>An IP address that a project can associate with a VM so that the
        instance has the same public IP address each time that it boots. You
        create a pool of floating IP addresses and assign them to instances as
        they are launched to maintain a consistent IP address for maintaining
        DNS assignment.</para>
      </glossdef>
    </glossentry>

    <glossentry>
      <glossterm>Folsom</glossterm>
      <indexterm class="singular">
          <primary>Folsom</primary>
        </indexterm>

      <glossdef>
        <para>A grouped release of projects related to OpenStack that came out
        in the fall of 2012, the sixth release of OpenStack. It includes
        Compute (nova), Object Storage (swift), Identity (keystone),
        Networking (neutron), Image Service (glance), and Volumes or Block
        Storage (cinder).</para>
        <para>Folsom is the code name for the sixth release of
        OpenStack. The design summit took place in
        San Francisco, California, US and Folsom is a nearby city.
        </para>
      </glossdef>
    </glossentry>

    <glossentry>
      <glossterm>FormPost</glossterm>
      <indexterm class="singular">
          <primary>FormPost</primary>
        </indexterm>

      <glossdef>
        <para>Object Storage middleware that uploads (posts) an image through
        a form on a web page.</para>
      </glossdef>
    </glossentry>

    <glossentry>
      <glossterm>front end</glossterm>
      <indexterm class="singular">
          <primary>front end, definition of</primary>
        </indexterm>

      <glossdef>
        <para>The point where a user interacts with a service; can be an API
        endpoint, the horizon dashboard, or a command-line tool.</para>
      </glossdef>
    </glossentry>
  </glossdiv>

  <!-- .G. -->

  <glossdiv>
    <title>G</title>

    <glossentry>
      <glossterm>gateway</glossterm>
      <indexterm class="singular">
          <primary>gateway</primary>
        </indexterm>

      <glossdef>
        <para>An IP address, typically assigned to a router, that
        passes network traffic between different networks.</para>
      </glossdef>
    </glossentry>

    <glossentry>
      <glossterm>Generic Receive Offload (GRO)</glossterm>
      <indexterm class="singular">
          <primary>Generic Receive Offload (GRO)</primary>
        </indexterm>
      <glossdef>
        <para>Feature of certain network interface drivers that
        combines many smaller received packets into a large packet
        before delivery to the kernel IP stack.</para>
      </glossdef>
      </glossentry>

      <glossentry>
        <glossterm>generic routing encapsulation (GRE)</glossterm>
      <indexterm class="singular">
          <primary>generic routing encapsulation (GRE)</primary>
        </indexterm>
        <glossdef>
          <para>Protocol that encapsulates a wide variety of network
          layer protocols inside virtual point-to-point links.
          </para>
        </glossdef>
      </glossentry>

    <glossentry>
      <glossterm>glance</glossterm>

      <glossdef>
        <para>A core project that provides the OpenStack Image Service.</para>
      </glossdef>
    </glossentry>

    <glossentry>
      <glossterm>glance API server</glossterm>
      <indexterm class="singular">
          <primary>glance</primary>

          <secondary>glance API server</secondary>
        </indexterm>

      <glossdef>
        <para>Processes client requests for VMs, updates Image Service
        metadata on the registry server, and communicates with the store
        adapter to upload VM images from the back-end store.</para>
      </glossdef>
    </glossentry>

    <glossentry>
      <glossterm>glance registry</glossterm>
      <indexterm class="singular">
          <primary>glance</primary>

          <secondary>glance registry</secondary>
        </indexterm>

      <glossdef>
        <para>Alternative term for the Image Service image registry.</para>
      </glossdef>
    </glossentry>

    <glossentry>
      <glossterm>global endpoint template</glossterm>
      <indexterm class="singular">
          <primary>endpoints</primary>

          <secondary>global endpoint template</secondary>
        </indexterm>
      <indexterm class="singular">
          <primary>global endpoint template</primary>
        </indexterm>

      <glossdef>
        <para>The Identity Service endpoint template that contains services
        available to all tenants.</para>
      </glossdef>
    </glossentry>

    <glossentry>
      <glossterm>GlusterFS</glossterm>
      <indexterm class="singular">
          <primary>GlusterFS</primary>
        </indexterm>

      <glossdef>
        <para>A file system designed to aggregate NAS hosts, compatible with
        OpenStack.</para>
      </glossdef>
    </glossentry>

    <glossentry>
      <glossterm>golden image</glossterm>
      <indexterm class="singular">
          <primary>golden image</primary>
        </indexterm>

      <glossdef>
        <para>A method of operating system installation where a finalized disk
        image is created and then used by all nodes without
        modification.</para>
      </glossdef>
    </glossentry>

    <glossentry>
      <glossterm>Graphic Interchange Format (GIF)</glossterm>
      <indexterm class="singular">
          <primary>Graphic Interchange Format (GIF)</primary>
        </indexterm>

      <glossdef>
        <para>A type of image file that is commonly used for animated images
        on web pages.</para>
      </glossdef>
    </glossentry>

    <glossentry>
      <glossterm>Graphics Processing Unit (GPU)</glossterm>
      <indexterm class="singular">
          <primary>Graphics Processing Unit (GPU)</primary>
        </indexterm>

      <glossdef>
        <para>Choosing a host based on the existence of a GPU is currently
        unsupported in OpenStack.</para>
      </glossdef>
    </glossentry>

    <glossentry>
      <glossterm>Green Threads</glossterm>
      <indexterm class="singular">
          <primary>Green Threads</primary>
        </indexterm>

      <glossdef>
        <para>The cooperative threading model used by Python; reduces race
        conditions and only context switches when specific library calls are
        made. Each OpenStack service is its own thread.</para>
      </glossdef>
    </glossentry>

    <glossentry>
      <glossterm>Grizzly</glossterm>
      <indexterm class="singular">
          <primary>Grizzly</primary>
        </indexterm>

      <glossdef>
        <para>The code name for the seventh release of
        OpenStack. The design summit took place in
        San Diego, California, US and Grizzly is an element of the state flag of
        California.</para>
      </glossdef>
    </glossentry>

    <glossentry>
      <glossterm>guest OS</glossterm>
      <indexterm class="singular">
          <primary>guest OS</primary>
        </indexterm>

      <glossdef>
        <para>An operating system instance running under the control of a
        hypervisor.</para>
      </glossdef>
    </glossentry>
  </glossdiv>

  <!-- .H. -->

  <glossdiv>
    <title>H</title>

    <glossentry>
      <glossterm>Hadoop</glossterm>
      <indexterm class="singular">
          <primary>Hadoop</primary>
        </indexterm>

      <glossdef>
        <para>Apache Hadoop is an open source software framework that supports
        data-intensive distributed applications.</para>
      </glossdef>
    </glossentry>

    <glossentry>
      <glossterm>handover</glossterm>
      <indexterm class="singular">
          <primary>handover</primary>
        </indexterm>

      <glossdef>
        <para>An object state in Object Storage where a new replica of the
        object is automatically created due to a drive failure.</para>
      </glossdef>
    </glossentry>

    <glossentry>
      <glossterm>hard reboot</glossterm>
      <indexterm class="singular">
          <primary>hard reboot</primary>
        </indexterm>

      <glossdef>
        <para>A type of reboot where a physical or virtual power button is
        pressed as opposed to a graceful, proper shutdown of the operating
        system.</para>
      </glossdef>
    </glossentry>

    <glossentry>
      <glossterm>Havana</glossterm>
      <indexterm class="singular">
          <primary>Havana</primary>
        </indexterm>

      <glossdef>
        <para>The code name for the eighth release of OpenStack. The
        design summit took place in Portland, Oregon, US and Havana is
        an unincorporated community in Oregon.</para>
      </glossdef>
    </glossentry>

    <glossentry>
      <glossterm>heat</glossterm>
      <indexterm class="singular">
          <primary>heat</primary>
        </indexterm>

      <glossdef>
        <para>An integrated project that aims to orchestrate multiple cloud
        applications for OpenStack.</para>
      </glossdef>
    </glossentry>

    <glossentry>
      <glossterm>Heat Orchestration Template (HOT)</glossterm>
      <indexterm class="singular">
          <primary>Heat Orchestration Template (HOT)</primary>
        </indexterm>

      <glossdef>
        <para>Heat input in the format native to OpenStack.</para>
      </glossdef>
    </glossentry>

    <glossentry>
        <glossterm>health monitor</glossterm>
      <indexterm class="singular">
          <primary>health monitor</primary>
        </indexterm>

        <glossdef>
          <para>Determines whether back-end members of a VIP pool can
          process a request. A pool can have several health monitors
          associated with it. When a pool has several monitors
          associated with it, all monitors check each member of the
          pool. All monitors must declare a member to be healthy for
          it to stay active.</para>
        </glossdef>
    </glossentry>

    <glossentry>
      <glossterm>high availability (HA)</glossterm>
      <indexterm class="singular">
        <primary>high availability (HA)</primary>
      </indexterm>

      <glossdef>
        <para>
          A high availability system design approach and associated
          service implementation ensures that a prearranged level of
          operational performance will be met during a contractual
          measurement period. High availability systems seeks to
          minimize system downtime and data loss.
        </para>
      </glossdef>
    </glossentry>

    <glossentry>
      <glossterm>horizon</glossterm>

      <glossdef>
        <para>OpenStack project that provides a dashboard, which is a web
        interface.</para>
      </glossdef>
    </glossentry>

    <glossentry>
      <glossterm>horizon plug-in</glossterm>
      <indexterm class="singular">
          <primary>horizon plug-ins</primary>
        </indexterm>

      <glossdef>
        <para>A plug-in for the OpenStack dashboard (horizon).</para>
      </glossdef>
    </glossentry>

    <glossentry>
      <glossterm>host</glossterm>
      <indexterm class="singular">
          <primary>hosts, definition of</primary>
        </indexterm>

      <glossdef>
        <para>A physical computer, not a VM instance (node).</para>
      </glossdef>
    </glossentry>

    <glossentry>
      <glossterm>host aggregate</glossterm>
      <indexterm class="singular">
          <primary>host aggregate</primary>
        </indexterm>

      <glossdef>
        <para>A method to further subdivide availability zones into hypervisor
        pools, a collection of common hosts.</para>
      </glossdef>
    </glossentry>

    <glossentry>
      <glossterm>Host Bus Adapter (HBA)</glossterm>
      <indexterm class="singular">
          <primary>Host Bus Adapter (HBA)</primary>
        </indexterm>

      <glossdef>
        <para>Device plugged into a PCI slot, such as a fibre channel or
        network card.</para>
      </glossdef>
    </glossentry>

    <glossentry>
      <glossterm>HTTP</glossterm>
      <indexterm class="singular">
          <primary>HTTP (Hypertext Transfer Protocol)</primary>

          <secondary>basics of</secondary>
        </indexterm>

      <glossdef>
        <para>Hypertext Transfer Protocol. HTTP is an application protocol for
        distributed, collaborative, hypermedia information systems. It is the
        foundation of data communication for the World Wide Web. Hypertext is
        structured text that uses logical links (hyperlinks) between nodes
        containing text. HTTP is the protocol to exchange or transfer
        hypertext.</para>
      </glossdef>
    </glossentry>

    <glossentry>
      <glossterm>HTTPS</glossterm>
      <indexterm class="singular">
          <primary>HTTPS (Hypertext Transfer Protocol Secure)</primary>
        </indexterm>

      <glossdef>
        <para>Hypertext Transfer Protocol Secure (HTTPS) is a communications
        protocol for secure communication over a computer network, with
        especially wide deployment on the Internet. Technically, it is not a
        protocol in and of itself; rather, it is the result of simply layering
        the Hypertext Transfer Protocol (HTTP) on top of the SSL/TLS protocol,
        thus adding the security capabilities of SSL/TLS to standard HTTP
        communications.</para>
      </glossdef>
    </glossentry>

    <glossentry>
      <glossterm>hybrid cloud</glossterm>
      <indexterm class="singular">
          <primary>hybrid cloud</primary>
        </indexterm>

      <glossdef>
        <para>
          A hybrid cloud is a composition of two or more clouds
          (private, community or public) that remain distinct entities
          but are bound together, offering the benefits of multiple
          deployment models.  Hybrid cloud can also mean the ability
          to connect colocation, managed and/or dedicated services
          with cloud resources.
        </para>
      </glossdef>
    </glossentry>

    <glossentry>
      <glossterm>Hyper-V</glossterm>
      <indexterm class="singular">
          <primary>Hyper-V</primary>
        </indexterm>

      <glossdef>
        <para>One of the hypervisors supported by OpenStack.</para>
      </glossdef>
    </glossentry>

    <glossentry>
      <glossterm>hyperlink</glossterm>
      <indexterm class="singular">
          <primary>hyperlink</primary>
        </indexterm>

      <glossdef>
        <para>Any kind of text that contains a link to some other site,
        commonly found in documents where clicking on a word or words opens up
        a different website.</para>
      </glossdef>
    </glossentry>

    <glossentry>
      <glossterm>Hypertext Transfer Protocol (HTTP)</glossterm>

      <glossdef>
        <para>The protocol that tells browsers where to go to find
        information.</para>
      </glossdef>
    </glossentry>

    <glossentry>
      <glossterm>Hypertext Transfer Protocol Secure (HTTPS)</glossterm>

      <glossdef>
        <para>Encrypted HTTP communications using SSL or TLS; most OpenStack
        API endpoints and many inter-component communications support HTTPS
        communication.</para>
      </glossdef>
    </glossentry>

    <glossentry>
      <glossterm>hypervisor</glossterm>
      <indexterm class="singular">
          <primary>hypervisors</primary>

          <secondary>definition of</secondary>
        </indexterm>

      <glossdef>
        <para>Software that arbitrates and controls VM access to the actual
        underlying hardware.</para>
      </glossdef>
    </glossentry>

    <glossentry>
      <glossterm>hypervisor pool</glossterm>
      <indexterm class="singular">
          <primary>hypervisors</primary>

          <secondary>hypervisor pools</secondary>
        </indexterm>

      <glossdef>
        <para>A collection of hypervisors grouped together through host
        aggregates.</para>
      </glossdef>
    </glossentry>
  </glossdiv>

  <!-- .I. -->

  <glossdiv>
    <title>I</title>

    <glossentry>
      <glossterm>IaaS</glossterm>
      <indexterm class="singular">
          <primary>IaaS (Infrastructure-as-a-Service)</primary>

          <secondary>basics of</secondary>
        </indexterm>

      <glossdef>
        <para>Infrastructure-as-a-Service. IaaS is a provisioning model in
        which an organization outsources physical components of a data center,
        such as storage, hardware, servers, and networking components. A
        service provider owns the equipment and is responsible for housing,
        operating and maintaining it. The client typically pays on a per-use
        basis. IaaS is a model for providing cloud services.</para>
      </glossdef>
    </glossentry>

    <glossentry>
      <glossterm>Icehouse</glossterm>
      <indexterm class="singular">
          <primary>Icehouse</primary>

          <secondary>definition of</secondary>
        </indexterm>

      <glossdef>
        <para>The code name for the ninth release of OpenStack. The
        design summit took place in Hong Kong and Ice House is a
        street in that city.</para>
      </glossdef>
    </glossentry>

    <glossentry>
        <glossterm>ICMP</glossterm>
      <indexterm class="singular">
          <primary>Internet Control Message Protocol (ICMP)</primary>
        </indexterm>

        <glossdef>
            <para>Internet Control Message Protocol, used by network
            devices for control messages. For example,
            <command>ping</command> uses ICMP to test
            connectivity.</para>
        </glossdef>
    </glossentry>

    <glossentry>
      <glossterm>ID number</glossterm>
      <indexterm class="singular">
          <primary>ID number</primary>
        </indexterm>

      <glossdef>
        <para>Unique numeric ID associated with each user in Identity Service,
        conceptually similar to a Linux or LDAP UID.</para>
      </glossdef>
    </glossentry>

    <glossentry>
      <glossterm>Identity API</glossterm>

      <glossdef>
        <para>Alternative term for the Identity Service API.</para>
      </glossdef>
    </glossentry>

    <glossentry>
      <glossterm>Identity back end</glossterm>
      <indexterm class="singular">
          <primary>Identity Service</primary>

          <secondary>Identity back end</secondary>
        </indexterm>

      <glossdef>
        <para>The source used by Identity Service to retrieve user
        information; an OpenLDAP server, for example.</para>
      </glossdef>
    </glossentry>

    <glossentry>
      <glossterm>Identity Service</glossterm>
      <indexterm class="singular">
          <primary>Identity Service</primary>

          <secondary>basics of</secondary>
        </indexterm>

      <glossdef>
        <para>The OpenStack core project that provides a central directory of
        users mapped to the OpenStack services they can access. It also
        registers endpoints for OpenStack services. It acts as a common
        authentication system. The project name of the Identity Service is
        keystone.</para>
      </glossdef>
    </glossentry>

    <glossentry>
      <glossterm>Identity Service API</glossterm>
      <indexterm class="singular">
          <primary>Identity Service</primary>

          <secondary>Identity Service API</secondary>
        </indexterm>

      <glossdef>
        <para>The API used to access the OpenStack Identity Service provided
        through keystone.</para>
      </glossdef>
    </glossentry>

    <glossentry>
      <glossterm>IDS</glossterm>
      <indexterm class="singular">
          <primary>IDS (Intrusion Detection System)</primary>
        </indexterm>

      <glossdef>
        <para>Intrusion Detection System.</para>
      </glossdef>
    </glossentry>

    <glossentry>
      <glossterm>image</glossterm>
      <indexterm class="singular">
          <primary>images</primary>

          <secondary>definition of</secondary>
        </indexterm>

      <glossdef>
        <para>A collection of files for a specific operating system (OS) that
        you use to create or rebuild a server. OpenStack provides pre-built
        images. You can also create custom images, or snapshots, from servers
        that you have launched. Custom images can be used for data backups or
        as "gold" images for additional servers.</para>
      </glossdef>
    </glossentry>

    <glossentry>
      <glossterm>Image API</glossterm>
      <indexterm class="singular">
          <primary>Image Service</primary>

          <secondary>Image Service API</secondary>
        </indexterm>

      <glossdef>
        <para>The Image Service API endpoint for management of VM
        images.</para>
      </glossdef>
    </glossentry>

    <glossentry>
      <glossterm>image cache</glossterm>
      <indexterm class="singular">
          <primary>Image Service</primary>

          <secondary>image cache</secondary>
        </indexterm>

      <glossdef>
        <para>Used by Image Service to obtain images on the local host rather
        than re-downloading them from the image server each time one is
        requested.</para>
      </glossdef>
    </glossentry>

    <glossentry>
      <glossterm>image ID</glossterm>
      <indexterm class="singular">
          <primary>Identity Service</primary>

          <secondary>image ID</secondary>
        </indexterm>

      <glossdef>
        <para>Combination of a URI and UUID used to access Image Service VM
        images through the image API.</para>
      </glossdef>
    </glossentry>

    <glossentry>
      <glossterm>image membership</glossterm>
      <indexterm class="singular">
          <primary>Image Service</primary>

          <secondary>image membership</secondary>
        </indexterm>

      <glossdef>
        <para>A list of tenants that can access a given VM image within Image
        Service.</para>
      </glossdef>
    </glossentry>

    <glossentry>
      <glossterm>image owner</glossterm>
      <indexterm class="singular">
          <primary>Image Service</primary>

          <secondary>image owner</secondary>
        </indexterm>

      <glossdef>
        <para>The tenant who owns an Image Service virtual machine
        image.</para>
      </glossdef>
    </glossentry>

    <glossentry>
      <glossterm>image registry</glossterm>
      <indexterm class="singular">
          <primary>Image Service</primary>

          <secondary>image registry</secondary>
        </indexterm>

      <glossdef>
        <para>A list of VM images that are available through Image
        Service.</para>
      </glossdef>
    </glossentry>

    <glossentry>
      <glossterm>Image Service</glossterm>

      <glossdef>
        <para>An OpenStack core project that provides discovery, registration,
        and delivery services for disk and server images. The project name of
        the Image Service is glance.</para>
      </glossdef>
    </glossentry>

    <glossentry>
      <glossterm>Image Service API</glossterm>

      <glossdef>
        <para>Alternative name for the glance image API.</para>
      </glossdef>
    </glossentry>

    <glossentry>
      <glossterm>image status</glossterm>
      <indexterm class="singular">
          <primary>Image Service</primary>

          <secondary>image status</secondary>
        </indexterm>

      <glossdef>
        <para>The current status of a VM image in Image Service, not to be
        confused with the status of a running instance.</para>
      </glossdef>
    </glossentry>

    <glossentry>
      <glossterm>image store</glossterm>
      <indexterm class="singular">
          <primary>Image Service</primary>

          <secondary>image store</secondary>
        </indexterm>

      <glossdef>
        <para>The back-end store used by Image Service to store VM images,
        options include Object Storage, local file system, S3, or HTTP.</para>
      </glossdef>
    </glossentry>

    <glossentry>
      <glossterm>image UUID</glossterm>
      <indexterm class="singular">
          <primary>Image Service</primary>

          <secondary>image UUID</secondary>
        </indexterm>

      <glossdef>
        <para>UUID used by Image Service to uniquely identify each VM
        image.</para>
      </glossdef>
    </glossentry>

    <glossentry>
      <glossterm>incubated project</glossterm>
      <indexterm class="singular">
          <primary>incubated projects</primary>
        </indexterm>

      <glossdef>
        <para>A community project may be elevated to this status and is then
        promoted to a core project.</para>
      </glossdef>
    </glossentry>

    <glossentry>
      <glossterm>ingress filtering</glossterm>
      <indexterm class="singular">
          <primary>filtering</primary>

          <secondary>ingress filtering</secondary>
        </indexterm>
      <indexterm class="singular">
          <primary>ingress filtering</primary>
        </indexterm>

      <glossdef>
        <para>The process of filtering incoming network traffic. Supported by
        Compute.</para>
      </glossdef>
    </glossentry>

    <glossentry>
      <glossterm>INI</glossterm>
      <indexterm class="singular">
          <primary>INI</primary></indexterm>

      <glossdef>
        <para>
          The OpenStack configuration files use an INI format to
          describe options and their values. It consists of sections
          and key value pairs.
        </para>
      </glossdef>
    </glossentry>

    <glossentry>
      <glossterm>injection</glossterm>
      <indexterm class="singular">
          <primary>injection</primary>
        </indexterm>

      <glossdef>
        <para>The process of putting a file into a virtual machine image
        before the instance is started.</para>
      </glossdef>
    </glossentry>

    <glossentry>
      <glossterm>instance</glossterm>
      <indexterm class="singular">
          <primary>instances</primary>

          <secondary>definition of</secondary>
        </indexterm>

      <glossdef>
        <para>A running VM, or a VM in a known state such as suspended, that
        can be used like a hardware server.</para>
      </glossdef>
    </glossentry>

    <glossentry>
      <glossterm>instance ID</glossterm>
      <indexterm class="singular">
          <primary>instances</primary>

          <secondary>instance ID</secondary>
        </indexterm>

      <glossdef>
        <para>Alternative term for instance UUID.</para>
      </glossdef>
    </glossentry>

    <glossentry>
      <glossterm>instance state</glossterm>
      <indexterm class="singular">
          <primary>instances</primary>

          <secondary>instance state</secondary>
        </indexterm>

      <glossdef>
        <para>The current state of a guest VM image.</para>
      </glossdef>
    </glossentry>

    <glossentry>
      <glossterm>instance tunnels network</glossterm>
      <indexterm class="singular">
          <primary>instance tunnels network</primary></indexterm>

      <glossdef>
        <para>A network segment used for instance traffic tunnels
        between compute nodes and the network node.</para>
      </glossdef>
    </glossentry>

    <glossentry>
      <glossterm>instance type</glossterm>
      <indexterm class="singular">
          <primary>instances</primary>

          <secondary>instance type</secondary>
        </indexterm>

      <glossdef>
        <para>Describes the parameters of the various virtual machine images
        that are available to users; includes parameters such as CPU, storage,
        and memory. Alternative term for flavor.</para>
      </glossdef>
    </glossentry>

    <glossentry>
      <glossterm>instance type ID</glossterm>
      <indexterm class="singular">
          <primary>instances</primary>

          <secondary>instance type ID</secondary>
        </indexterm>

      <glossdef>
        <para>Alternative term for a flavor ID.</para>
      </glossdef>
    </glossentry>

    <glossentry>
      <glossterm>instance UUID</glossterm>
      <indexterm class="singular">
          <primary>instances</primary>

          <secondary>instance UUID</secondary>
        </indexterm>

      <glossdef>
        <para>Unique ID assigned to each guest VM <phrase
        role="keep-together">instance</phrase>.</para>
      </glossdef>
    </glossentry>

    <glossentry>
      <glossterm>interface</glossterm>
      <indexterm class="singular">
          <primary>interface</primary>
        </indexterm>

      <glossdef>
        <para>A physical or virtual device that provides connectivity
        to another device or medium.</para>
      </glossdef>
    </glossentry>

    <glossentry>
      <glossterm>interface ID</glossterm>
      <indexterm class="singular">
          <primary>interface ID</primary>
        </indexterm>

      <glossdef>
        <para>Unique ID for a Networking VIF or vNIC in the form of a
        UUID.</para>
      </glossdef>
    </glossentry>

    <glossentry>
      <glossterm>internet protocol (IP)</glossterm>
      <indexterm class="singular">
        <primary>internet protocol (IP)</primary>
      </indexterm>

      <glossdef>
        <para>Principal communications protocol in the internet protocol
          suite for relaying datagrams across network boundaries.</para>
      </glossdef>
    </glossentry>

    <glossentry>
      <glossterm>Internet Service Provider (ISP)</glossterm>
      <indexterm class="singular">
          <primary>Internet Service Provider (ISP)</primary>
        </indexterm>

      <glossdef>
        <para>Any business that provides Internet access to individuals or
        businesses.</para>
      </glossdef>
    </glossentry>

    <glossentry>
      <glossterm>Internet Small Computer System Interface (iSCSI)</glossterm>
      <indexterm class="singular">
        <primary>Internet Small Computer System Interface (iSCSI)</primary>
      </indexterm>

      <glossdef>
        <para>Storage protocol that encapsulates SCSI frames for transport
          over IP networks.</para>
      </glossdef>
    </glossentry>

    <glossentry>
      <glossterm>ironic</glossterm>
      <indexterm class="singular">
          <primary>ironic</primary>
        </indexterm>

      <glossdef>
        <para>OpenStack project that provisions bare metal, as opposed to
        virtual, machines.</para>
      </glossdef>
    </glossentry>

    <glossentry>
      <glossterm>IOPS</glossterm>
      <indexterm class="singular">
          <primary>IOPS</primary>

          <secondary>definition of</secondary>
        </indexterm>

      <glossdef>
        <para>
          IOPS (Input/Output Operations Per Second) are a common
          performance measurement used to benchmark computer storage
          devices like hard disk drives, solid state drives, and
          storage area networks.
        </para>
      </glossdef>
    </glossentry>

    <glossentry>
      <glossterm>IP address</glossterm>
      <indexterm class="singular">
          <primary>IP addresses</primary>

          <secondary>definition of</secondary>
        </indexterm>

      <glossdef>
        <para>Number that is unique to every computer system on the Internet.
        Two versions of the Internet Protocol (IP) are in use for addresses:
        IPv4 and IPv6.</para>
      </glossdef>
    </glossentry>

    <glossentry>
      <glossterm>IP Address Management (IPAM)</glossterm>
      <indexterm class="singular">
          <primary>IP Address Management (IPAM)</primary>
        </indexterm>

      <glossdef>
        <para>The process of automating IP address allocation, deallocation,
        and management. Currently provided by Compute, melange, and
        Networking.</para>
      </glossdef>
    </glossentry>

    <glossentry>
      <glossterm>IPL</glossterm>
      <indexterm class="singular">
          <primary>IPL (Initial Program Loader)</primary>
        </indexterm>

      <glossdef>
        <para>Initial Program Loader.</para>
      </glossdef>
    </glossentry>

    <glossentry>
      <glossterm>IPMI</glossterm>
      <indexterm class="singular">
          <primary>IPMI (Intelligent Platform Management Interface)</primary>
        </indexterm>

      <glossdef>
        <para>Intelligent Platform Management Interface. IPMI is a
        standardized computer system interface used by system administrators
        for out-of-band management of computer systems and monitoring of their
        <phrase role="keep-together">operation</phrase>. In layman's terms, it
        is a way to manage a computer using a direct network connection,
        whether it is turned on or not; connecting to the hardware rather than
        an operating system or login shell.</para>
      </glossdef>
    </glossentry>

    <glossentry>
      <glossterm>ip6tables</glossterm>
      <indexterm class="singular">
          <primary>ip6tables</primary>
        </indexterm>

      <glossdef>
        <para>Tool used to set up, maintain, and inspect the tables of IPv6
        packet filter rules in the Linux kernel. In OpenStack Compute,
        ip6tables is used along with arptables, ebtables, and iptables to
        create firewalls for both nodes and VMs.</para>
      </glossdef>
    </glossentry>

    <glossentry>
      <glossterm>iptables</glossterm>
      <indexterm class="singular">
          <primary>iptables</primary>
        </indexterm>

      <glossdef>
        <para>Used along with arptables and ebtables, iptables create
        firewalls in Compute. iptables are the tables provided by the Linux
        kernel firewall (implemented as different Netfilter modules) and the
        chains and rules it stores. Different kernel modules and programs are
        currently used for different protocols: iptables applies to IPv4,
        ip6tables to IPv6, arptables to ARP, and ebtables to Ethernet frames.
        Requires root privilege to manipulate.</para>
      </glossdef>
    </glossentry>

    <glossentry>
      <glossterm>iSCSI</glossterm>
      <indexterm class="singular">
          <primary>iSCSI protocol</primary>
        </indexterm>

      <glossdef>
        <para>The SCSI disk protocol tunneled within Ethernet, supported by
        Compute, Object Storage, and Image Service.</para>
      </glossdef>
    </glossentry>

    <glossentry>
      <glossterm>ISO9960</glossterm>
      <indexterm class="singular">
          <primary>ISO9960 format</primary>
        </indexterm>

      <glossdef>
        <para>One of the VM image disk formats supported by Image
        Service.</para>
      </glossdef>
    </glossentry>

    <glossentry>
      <glossterm>itsec</glossterm>
      <indexterm class="singular">
          <primary>itsec</primary>
        </indexterm>

      <glossdef>
        <para>A default role in the Compute RBAC system that can quarantine an
        instance in any project.</para>
      </glossdef>
    </glossentry>
  </glossdiv>

  <!-- .J. -->

  <glossdiv>
    <title>J</title>

    <glossentry>
      <glossterm>Java</glossterm>
      <indexterm class="singular">
          <primary>Java</primary>
        </indexterm>

      <glossdef>
        <para>A programming language that is used to create systems that
        involve more than one computer by way of a network.</para>
      </glossdef>
    </glossentry>

    <glossentry>
      <glossterm>JavaScript</glossterm>
      <indexterm class="singular">
          <primary>JavaScript</primary>
        </indexterm>

      <glossdef>
        <para>A scripting language that is used to build web pages.</para>
      </glossdef>
    </glossentry>

    <glossentry>
      <glossterm>JavaScript Object Notation (JSON)</glossterm>
      <indexterm class="singular">
          <primary>JavaScript Object Notation (JSON)</primary>
        </indexterm>

      <glossdef>
        <para>One of the supported response formats in OpenStack.</para>
      </glossdef>
    </glossentry>

    <glossentry>
      <glossterm>Jenkins</glossterm>
      <indexterm class="singular">
          <primary>Jenkins</primary>
        </indexterm>

      <glossdef>
        <para>Tool used to run jobs automatically for OpenStack
        development.</para>
      </glossdef>
    </glossentry>

    <glossentry>
      <glossterm>jumbo frame</glossterm>
      <indexterm class="singular">
        <primary>jumbo frame</primary>
      </indexterm>

      <glossdef>
        <para>Feature in modern Ethernet networks that supports frames up to
          approximately 9000 bytes.</para>
      </glossdef>
    </glossentry>

    <glossentry>
      <glossterm>Juno</glossterm>
      <indexterm class="singular">
          <primary>Juno</primary>
        </indexterm>

      <glossdef>
        <para>The code name for the tenth release of OpenStack. The
        design summit took place in Atlanta, Georgia, US and Juno is
        an unincorporated community in Georgia.</para>
      </glossdef>
    </glossentry>
  </glossdiv>

  <!-- .K. -->

  <glossdiv>
    <title>K</title>

    <glossentry>
      <glossterm>kernel-based VM (KVM)</glossterm>
      <indexterm class="singular">
          <primary>kernel-based VM (KVM) hypervisor</primary>
        </indexterm>

      <glossdef>
        <para>
          An OpenStack-supported hypervisor. KVM is a full
          virtualization solution for Linux on x86 hardware containing
          virtualization extensions (Intel VT or AMD-V), ARM, IBM
          Power, and IBM zSeries. It consists of a loadable kernel
          module, that provides the core virtualization infrastructure
          and a processor specific module.
        </para>
      </glossdef>
    </glossentry>

    <glossentry>
      <glossterm>keystone</glossterm>
      <indexterm class="singular">
          <primary>keystone</primary>
        </indexterm>

      <glossdef>
        <para>The project that provides OpenStack Identity services.</para>
      </glossdef>
    </glossentry>

    <glossentry>
      <glossterm>Kickstart</glossterm>
      <indexterm class="singular">
          <primary>Kickstart</primary>
        </indexterm>

      <glossdef>
        <para>A tool to automate system configuration and installation on Red
        Hat, Fedora, and CentOS-based Linux distributions.</para>
      </glossdef>
    </glossentry>

    <glossentry>
      <glossterm>Kilo</glossterm>
      <indexterm class="singular">
          <primary>Kilo</primary>
        </indexterm>

      <glossdef>
        <para>The code name for the eleventh release of OpenStack. The
        design summit took place in Paris, France. Due to delays in the name
        selection, the release was known only as K. Because <literal>k</literal> is the
        unit symbol for kilo and the reference artifact is stored near Paris
        in the Pavillon de Breteuil in Sèvres, the community chose Kilo as
        the release name.</para>
      </glossdef>
    </glossentry>
  </glossdiv>

  <!-- .L. -->

  <glossdiv>
    <title>L</title>

    <glossentry>
      <glossterm>large object</glossterm>
      <indexterm class="singular">
          <primary>large object</primary>
        </indexterm>

      <glossdef>
        <para>An object within Object Storage that is larger than 5&nbsp;GB.</para>
      </glossdef>
    </glossentry>

    <glossentry>
      <glossterm>Launchpad</glossterm>
      <indexterm class="singular">
          <primary>Launchpad</primary>
        </indexterm>

      <glossdef>
        <para>The collaboration site for OpenStack.</para>
      </glossdef>
    </glossentry>

    <glossentry>
      <glossterm>Layer-2 network</glossterm>
      <indexterm class="singular">
          <primary>Layer-2 network</primary>
        </indexterm>

      <glossdef>
        <para>
          Term used in the OSI network architecture for the data link
          layer. The data link layer is responsible for media access
          control, flow control and detecting and possibly correcting
          erros that may occur in the physical layer.
        </para>
      </glossdef>
    </glossentry>

    <glossentry>
      <glossterm>Layer-3 network</glossterm>
      <indexterm class="singular">
          <primary>Layer-3 network</primary>
        </indexterm>

      <glossdef>
        <para>
          Term used in the OSI network architecture for the network
          layer. The network layer is responsible for packet
          forwarding including routing from one node to another.
        </para>
      </glossdef>
    </glossentry>

    <glossentry>
      <glossterm>Layer-2 (L2) agent</glossterm>
      <indexterm class="singular">
          <primary>Layer-2 (L2) agent</primary>
        </indexterm>

      <glossdef>
        <para>OpenStack Networking agent that provides layer-2
        connectivity for virtual networks.</para>
      </glossdef>
    </glossentry>

    <glossentry>
      <glossterm>Layer-3 (L3) agent</glossterm>
      <indexterm class="singular">
          <primary>Layer-3 (L3) agent</primary>
        </indexterm>

      <glossdef>
        <para>OpenStack Networking agent that provides layer-3
        (routing) services for virtual networks.</para>
      </glossdef>
    </glossentry>

    <glossentry>
      <glossterm>libvirt</glossterm>
      <indexterm class="singular">
          <primary>libvirt</primary>
        </indexterm>

      <glossdef>
        <para>Virtualization API library used by OpenStack to interact with
        many of its supported hypervisors.</para>
      </glossdef>
    </glossentry>

    <glossentry>
      <glossterm>Linux bridge</glossterm>

      <glossdef>
        <para>Software that enables multiple VMs to share a single physical
        NIC within Compute.</para>
      </glossdef>
    </glossentry>

    <glossentry>
      <glossterm>Linux Bridge neutron plug-in</glossterm>
      <indexterm class="singular">
          <primary>Linux Bridge</primary>

          <secondary>neutron plug-in for</secondary>
        </indexterm>

      <glossdef>
        <para>Enables a Linux bridge to understand a Networking port,
        interface attachment, and other abstractions.</para>
      </glossdef>
    </glossentry>

    <glossentry>
      <glossterm>Linux containers (LXC)</glossterm>
      <indexterm class="singular">
          <primary>Linux containers (LXC)</primary>
        </indexterm>

      <glossdef>
        <para>An OpenStack-supported hypervisor.</para>
      </glossdef>
    </glossentry>

    <glossentry>
      <glossterm>live migration</glossterm>
      <indexterm class="singular">
          <primary>live migration</primary>
        </indexterm>

      <glossdef>
        <para>The ability within Compute to move running virtual machine
        instances from one host to another with only a small service
        interruption during switchover.</para>
      </glossdef>
    </glossentry>

    <glossentry>
      <glossterm>load balancer</glossterm>

      <glossdef>
        <para>A load balancer is a logical device that belongs to a cloud
        account. It is used to distribute workloads between multiple back-end
        systems or services, based on the criteria defined as part of its
        configuration.</para>
      </glossdef>
    </glossentry>

    <glossentry>
      <glossterm>load balancing</glossterm>
      <indexterm class="singular">
          <primary>load balancing</primary>
        </indexterm>

      <glossdef>
        <para>The process of spreading client requests between two or more
        nodes to improve performance and availability.</para>
      </glossdef>
    </glossentry>

    <glossentry>
      <glossterm>Load-Balancer-as-a-Service (LBaaS)</glossterm>
      <indexterm
          class="singular">
          <primary>Load-Balancer-as-a-Service (LBaaS)</primary>
        </indexterm>

      <glossdef>
        <para>Enables Networking to distribute incoming requests evenly
        between designated instances.</para>
      </glossdef>
    </glossentry>

    <glossentry>
      <glossterm>Logical Volume Manager (LVM)</glossterm>
      <indexterm class="singular">
          <primary>Logical Volume Manager (LVM)</primary>
        </indexterm>

      <glossdef>
        <para>Provides a method of allocating space on mass-storage
        devices that is more flexible than conventional partitioning
        schemes.</para>
      </glossdef>
    </glossentry>
  </glossdiv>

  <!-- .M. -->

  <glossdiv>
    <title>M</title>

    <glossentry>
      <glossterm>management API</glossterm>
      <indexterm class="singular">
          <primary>management API</primary>

          <see>admin API</see>
        </indexterm>

      <glossdef>
        <para>Alternative term for an admin API.</para>
      </glossdef>
    </glossentry>

    <glossentry>
      <glossterm>management network</glossterm>
      <indexterm class="singular">
          <primary>management network</primary>
        </indexterm>

      <glossdef>
        <para>A network segment used for administration, not accessible to the
        public Internet.</para>
      </glossdef>
    </glossentry>

    <glossentry>
      <glossterm>manager</glossterm>
      <indexterm class="singular">
          <primary>manager</primary>
        </indexterm>

      <glossdef>
        <para>Logical groupings of related code, such as the Block Storage
        volume manager or network manager.</para>
      </glossdef>
    </glossentry>

    <glossentry>
      <glossterm>manifest</glossterm>
      <indexterm class="singular">
          <primary>manifests</primary>

          <secondary>definition of</secondary>
        </indexterm>

      <glossdef>
        <para>Used to track segments of a large object within Object
        Storage.</para>
      </glossdef>
    </glossentry>

    <glossentry>
      <glossterm>manifest object</glossterm>
      <indexterm class="singular">
          <primary>objects</primary>

          <secondary>manifest objects</secondary>
        </indexterm>
      <indexterm class="singular">
          <primary>manifests</primary>

          <secondary>manifest objects</secondary>
        </indexterm>

      <glossdef>
        <para>A special Object Storage object that contains the manifest for a
        large object.</para>
      </glossdef>
    </glossentry>

    <glossentry>
      <glossterm>marconi</glossterm>
      <indexterm class="singular">
          <primary>marconi</primary>
        </indexterm>

      <glossdef>
        <para>OpenStack project that provides a queue service to
        applications.</para>
      </glossdef>
    </glossentry>

    <glossentry>
      <glossterm>maximum transmission unit (MTU)</glossterm>
      <indexterm class="singular">
        <primary>maximum transmission unit (MTU)</primary>
      </indexterm>

      <glossdef>
        <para>Maximum frame or packet size for a particular network
          medium. Typically 1500 bytes for Ethernet networks.</para>
      </glossdef>
    </glossentry>

    <glossentry>
      <glossterm>mechanism driver</glossterm>
      <indexterm class="singular">
        <primary>mechanism driver</primary>
      </indexterm>

      <glossdef>
        <para>
          A driver for the Modular Layer 2 (ML2) neutron plug-in that
          provides layer-2 connectivity for virtual instances. A
          single OpenStack installation can use multiple mechanism
          drivers.
        </para>
      </glossdef>
    </glossentry>
    <glossentry>
      <glossterm>melange</glossterm>
      <indexterm class="singular">
          <primary>melange</primary>
        </indexterm>

      <glossdef>
        <para>Project name for OpenStack Network Information Service. To be
        merged with Networking.</para>
      </glossdef>
    </glossentry>

    <glossentry>
      <glossterm>membership</glossterm>
      <indexterm class="singular">
          <primary>membership</primary>
        </indexterm>

      <glossdef>
        <para>The association between an Image Service VM image and a tenant.
        Enables images to be shared with specified tenants.</para>
      </glossdef>
    </glossentry>

    <glossentry>
      <glossterm>membership list</glossterm>
      <indexterm class="singular">
          <primary>membership lists</primary>
        </indexterm>

      <glossdef>
        <para>A list of tenants that can access a given VM image within Image
        Service.</para>
      </glossdef>
    </glossentry>

    <glossentry>
      <glossterm>memcached</glossterm>
      <indexterm class="singular">
          <primary>memcached</primary>
        </indexterm>

      <glossdef>
        <para>A distributed memory object caching system that is used by
        Object Storage for caching.</para>
      </glossdef>
    </glossentry>

    <glossentry>
      <glossterm>memory overcommit</glossterm>
      <indexterm class="singular">
          <primary>memory overcommit</primary>
        </indexterm>

      <glossdef>
        <para>The ability to start new VM instances based on the actual memory
        usage of a host, as opposed to basing the decision on the amount of
        RAM each running instance thinks it has available. Also known as RAM
        overcommit.</para>
      </glossdef>
    </glossentry>

    <glossentry>
      <glossterm>message broker</glossterm>
      <indexterm class="singular">
          <primary>message brokers</primary>
        </indexterm>

      <glossdef>
        <para>The software package used to provide AMQP messaging capabilities
        within Compute. Default package is RabbitMQ.</para>
      </glossdef>
    </glossentry>

    <glossentry>
      <glossterm>message bus</glossterm>
      <indexterm class="singular">
          <primary>message bus</primary>
        </indexterm>

      <glossdef>
        <para>The main virtual communication line used by all AMQP messages
        for inter-cloud communications within Compute.</para>
      </glossdef>
    </glossentry>

    <glossentry>
      <glossterm>message queue</glossterm>
      <indexterm class="singular">
          <primary>message queue</primary>
        </indexterm>

      <glossdef>
        <para>Passes requests from clients to the appropriate workers and
        returns the output to the client after the job completes.</para>
      </glossdef>
    </glossentry>

    <glossentry>
      <glossterm>Metadata agent</glossterm>
      <indexterm class="singular">
          <primary>Metadata agent</primary>
        </indexterm>

      <glossdef>
        <para>OpenStack Networking agent that provides metadata
        services for instances.</para>
      </glossdef>
    </glossentry>

    <glossentry>
      <glossterm>Meta-Data Server (MDS)</glossterm>
      <indexterm class="singular">
          <primary>Meta-Data Server (MDS)</primary>
        </indexterm>

      <glossdef>
        <para>Stores CephFS metadata.</para>
      </glossdef>
    </glossentry>

    <glossentry>
      <glossterm>migration</glossterm>
      <indexterm class="singular">
          <primary>migration</primary>
        </indexterm>

      <glossdef>
        <para>The process of moving a VM instance from one host to
        another.</para>
      </glossdef>
    </glossentry>

    <glossentry>
      <glossterm>multi-host</glossterm>
      <indexterm class="singular">
          <primary>multi-host</primary>
        </indexterm>

      <glossdef>
        <para>High-availability mode for legacy (nova) networking.
        Each compute node handles NAT and DHCP and acts as a gateway
        for all of the VMs on it. A networking failure on one compute
        node doesn't affect VMs on other compute nodes.</para>
      </glossdef>
    </glossentry>

    <glossentry>
      <glossterm>multinic</glossterm>

      <glossdef>
        <para>Facility in Compute that allows each virtual machine instance to
        have more than one VIF connected to it.</para>
      </glossdef>
    </glossentry>

    <glossentry>
      <glossterm>Modular Layer 2 (ML2) neutron plug-in</glossterm>
      <indexterm
          class="singular">
          <primary>Modular Layer 2 (ML2) neutron plug-in</primary>
        </indexterm>

      <glossdef>
        <para>Can concurrently use multiple layer-2 networking technologies,
        such as 802.1Q and VXLAN, in Networking.</para>
      </glossdef>
    </glossentry>

    <glossentry>
      <glossterm>Monitor (LBaaS)</glossterm>
      <indexterm class="singular">
          <primary>Monitor (LBaaS)</primary>
        </indexterm>

      <glossdef>
        <para>LBaaS feature that provides availability monitoring using the
        <literal>ping</literal> command, TCP, and HTTP/HTTPS GET.</para>
      </glossdef>
    </glossentry>

    <glossentry>
      <glossterm>Monitor (Mon)</glossterm>
      <indexterm class="singular">
          <primary>Monitor (Mon)</primary>
        </indexterm>

      <glossdef>
        <para>A Ceph component that communicates with external clients, checks
        data state and consistency, and performs quorum functions.</para>
      </glossdef>
    </glossentry>

    <glossentry>
      <glossterm>multi-factor authentication</glossterm>
      <indexterm class="singular">
          <primary>multi-factor authentication</primary>
        </indexterm>

      <glossdef>
        <para>Authentication method that uses two or more credentials, such as
        a password and a private key. Currently not supported in Identity
        Service.</para>
      </glossdef>
    </glossentry>

    <glossentry>
      <glossterm>MultiNic</glossterm>
      <indexterm class="singular">
          <primary>MultiNic</primary>
        </indexterm>

      <glossdef>
        <para>Facility in Compute that enables a virtual machine instance to
        have more than one VIF connected to it.</para>
      </glossdef>
    </glossentry>
  </glossdiv>

  <!-- .N. -->

  <glossdiv>
    <title>N</title>

    <glossentry>
      <glossterm>Nebula</glossterm>
      <indexterm class="singular">
          <primary>Nebula</primary>
        </indexterm>

      <glossdef>
        <para>Released as open source by NASA in 2010 and is the basis for
        Compute.</para>
      </glossdef>
    </glossentry>

    <glossentry>
      <glossterm>netadmin</glossterm>
      <indexterm class="singular">
          <primary>netadmin</primary>
        </indexterm>

      <glossdef>
        <para>One of the default roles in the Compute RBAC system. Enables the
        user to allocate publicly accessible IP addresses to instances and
        change firewall rules.</para>
      </glossdef>
    </glossentry>

    <glossentry>
      <glossterm>NetApp volume driver</glossterm>
      <indexterm class="singular">
          <primary>NetApp volume driver</primary>
        </indexterm>

      <glossdef>
        <para>Enables Compute to communicate with NetApp storage devices
        through the <phrase role="keep-together">NetApp</phrase> OnCommand
        Provisioning <phrase role="keep-together">Manager</phrase>.</para>
      </glossdef>
    </glossentry>

    <glossentry>
      <glossterm>network</glossterm>
      <indexterm class="singular">
          <primary>networks</primary>

          <secondary>definition of</secondary>
        </indexterm>

      <glossdef>
        <para>A virtual network that provides connectivity between entities.
        For example, a collection of virtual ports that share network
        connectivity. In Networking terminology, a network is always a layer-2
        network.</para>
      </glossdef>
    </glossentry>

    <glossentry>
      <glossterm>Network Address Translation (NAT)</glossterm>
      <indexterm class="singular">
          <primary>networks</primary>

          <secondary>Network Address Translation (NAT)</secondary>
        </indexterm>

      <glossdef>
        <para>The process of modifying IP address information while in
        transit. Supported by Compute and Networking.</para>
      </glossdef>
    </glossentry>

    <glossentry>
      <glossterm>network controller</glossterm>
      <indexterm class="singular">
          <primary>networks</primary>

          <secondary>network controllers</secondary>
        </indexterm>

      <glossdef>
        <para>A Compute daemon that orchestrates the network configuration of
        nodes, including IP addresses, VLANs, and bridging. Also manages
        routing for both public and private networks.</para>
      </glossdef>
    </glossentry>

    <glossentry>
      <glossterm>Network File System (NFS)</glossterm>
      <indexterm class="singular">
          <primary>networks</primary>

          <secondary>Network File System (NFS)</secondary>
        </indexterm>

      <glossdef>
        <para>A method for making file systems available over the network.
        Supported by OpenStack.</para>
      </glossdef>
    </glossentry>

    <glossentry>
      <glossterm>network ID</glossterm>
      <indexterm class="singular">
          <primary>networks</primary>

          <secondary>network IDs</secondary>
        </indexterm>

      <glossdef>
        <para>Unique ID assigned to each network segment within Networking.
        Same as network UUID.</para>
      </glossdef>
    </glossentry>

    <glossentry>
      <glossterm>network manager</glossterm>
      <indexterm class="singular">
          <primary>networks</primary>

          <secondary>network managers</secondary>
        </indexterm>

      <glossdef>
        <para>The Compute component that manages various network components,
        such as firewall rules, IP address allocation, and so on.</para>
      </glossdef>
    </glossentry>

    <glossentry>
      <glossterm>network node</glossterm>
      <indexterm class="singular">
          <primary>networks</primary>

          <secondary>network nodes</secondary>
        </indexterm>

      <glossdef>
        <para>Any compute node that runs the network worker daemon.</para>
      </glossdef>
    </glossentry>

    <glossentry>
      <glossterm>network segment</glossterm>
      <indexterm class="singular">
          <primary>networks</primary>

          <secondary>network segments</secondary>
        </indexterm>

      <glossdef>
        <para>Represents a virtual, isolated OSI layer-2 subnet in
        Networking.</para>
      </glossdef>
    </glossentry>

    <glossentry>
      <glossterm>Network Time Protocol (NTP)</glossterm>
      <indexterm class="singular">
          <primary>networks</primary>

          <secondary>Network Time Protocol (NTP)</secondary>
        </indexterm>

      <glossdef>
        <para>A method of keeping a clock for a host or node correct through
        communications with a trusted, accurate time source.</para>
      </glossdef>
    </glossentry>

    <glossentry>
      <glossterm>network UUID</glossterm>
      <indexterm class="singular">
          <primary>networks</primary>

          <secondary>network UUID</secondary>
        </indexterm>

      <glossdef>
        <para>Unique ID for a Networking network <phrase
        role="keep-together">segment</phrase>.</para>
      </glossdef>
    </glossentry>

    <glossentry>
      <glossterm>network worker</glossterm>
      <indexterm class="singular">
          <primary>networks</primary>

          <secondary>network workers</secondary>
        </indexterm>

      <glossdef>
        <para>The <literal>nova-network</literal> worker daemon; provides
        services such as giving an IP address to a booting nova
        instance.</para>
      </glossdef>
    </glossentry>

    <glossentry>
      <glossterm>Networking</glossterm>

      <glossdef>
        <para>A core OpenStack project that provides a network connectivity
        abstraction layer to OpenStack Compute. The project name of Networking
        is neutron.</para>
      </glossdef>
    </glossentry>

    <glossentry>
      <glossterm>Networking API</glossterm>
      <indexterm class="singular">
          <primary>Networking API</primary>
        </indexterm>

      <glossdef>
        <para>API used to access OpenStack Networking. Provides an extensible
        architecture to enable custom plug-in creation.</para>
      </glossdef>
    </glossentry>

    <glossentry>
      <glossterm>neutron</glossterm>

      <glossdef>
        <para>A core OpenStack project that provides a network connectivity
        abstraction layer to OpenStack Compute.</para>
      </glossdef>
    </glossentry>

    <glossentry>
      <glossterm>neutron API</glossterm>
      <indexterm class="singular">
          <primary>neutron</primary>

          <secondary>Networking API</secondary>
        </indexterm>

      <glossdef>
        <para>An alternative name for Networking API.</para>
      </glossdef>
    </glossentry>

    <glossentry>
      <glossterm>neutron manager</glossterm>
      <indexterm class="singular">
          <primary>neutron</primary>

          <secondary>neutron manager</secondary>
        </indexterm>

      <glossdef>
        <para>Enables Compute and Networking integration, which enables
        Networking to perform network management for guest VMs.</para>
      </glossdef>
    </glossentry>

    <glossentry>
      <glossterm>neutron plug-in</glossterm>
      <indexterm class="singular">
          <primary>neutron</primary>

          <secondary>neutron plug-in</secondary>
        </indexterm>

      <glossdef>
        <para>Interface within Networking that enables organizations to create
        custom plug-ins for advanced features, such as QoS, ACLs, or
        IDS.</para>
      </glossdef>
    </glossentry>

    <glossentry>
      <glossterm>Nexenta volume driver</glossterm>
      <indexterm class="singular">
          <primary>Nexenta volume driver</primary>
        </indexterm>

      <glossdef>
        <para>Provides support for NexentaStor devices in Compute.</para>
      </glossdef>
    </glossentry>

    <glossentry>
      <glossterm>No ACK</glossterm>
      <indexterm class="singular">
          <primary>No ACK</primary>
        </indexterm>

      <glossdef>
        <para>Disables server-side message acknowledgment in the Compute
        RabbitMQ. Increases performance but decreases reliability.</para>
      </glossdef>
    </glossentry>

    <glossentry>
      <glossterm>node</glossterm>
      <indexterm class="singular">
          <primary>nodes</primary>

          <secondary>definition of</secondary>
        </indexterm>

      <glossdef>
        <para>A VM instance that runs on a host.</para>
      </glossdef>
    </glossentry>

    <glossentry>
      <glossterm>non-durable exchange</glossterm>
      <indexterm class="singular">
          <primary>messages</primary>

          <secondary>non-durable exchanges</secondary>
        </indexterm>
      <indexterm class="singular">
          <primary>non-durable exchanges</primary>
        </indexterm>

      <glossdef>
        <para>Message exchange that is cleared when the service restarts. Its
        data is not written to persistent storage.</para>
      </glossdef>
    </glossentry>

    <glossentry>
      <glossterm>non-durable queue</glossterm>
      <indexterm class="singular">
          <primary>messages</primary>

          <secondary>non-durable queues</secondary>
        </indexterm>
      <indexterm class="singular">
          <primary>non-durable queue</primary>
        </indexterm>

      <glossdef>
        <para>Message queue that is cleared when the service restarts. Its
        data is not written to persistent storage.</para>
      </glossdef>
    </glossentry>

    <glossentry>
      <glossterm>non-persistent volume</glossterm>
      <indexterm class="singular">
          <primary>non-persistent volume</primary>

          <see>ephemeral volume</see>
        </indexterm>

      <glossdef>
        <para>Alternative term for an ephemeral volume.</para>
      </glossdef>
    </glossentry>

    <glossentry>
      <glossterm>north-south traffic</glossterm>
      <indexterm class="singular">
        <primary>north-south traffic</primary>
      </indexterm>

      <glossdef>
        <para>
          Network traffic between a user or client (north) and a
          server (south), or traffic into the cloud (south) and
          out of the cloud (north). See also east-west traffic.
        </para>
      </glossdef>
    </glossentry>
    <glossentry>
      <glossterm>nova</glossterm>

      <glossdef>
        <para>OpenStack project that provides compute services.</para>
      </glossdef>
    </glossentry>

    <glossentry>
      <glossterm>Nova API</glossterm>
      <indexterm class="singular">
          <primary>nova</primary>

          <secondary>Compute API</secondary>
        </indexterm>

      <glossdef>
        <para>Alternative term for the Compute API.</para>
      </glossdef>
    </glossentry>

    <glossentry>
      <glossterm>nova-network</glossterm>
      <indexterm class="singular">
          <primary>nova</primary>

          <secondary>nova-network</secondary>
        </indexterm>

      <glossdef>
        <para>A Compute component that manages IP address allocation,
        firewalls, and other network-related tasks. This is the legacy
        networking option and an alternative to Networking.</para>
      </glossdef>
    </glossentry>
  </glossdiv>

  <!-- .O. -->

  <glossdiv>
    <title>O</title>

    <glossentry>
      <glossterm>object</glossterm>
      <indexterm class="singular">
          <primary>objects</primary>

          <secondary>definition of</secondary>
        </indexterm>

      <glossdef>
        <para>A BLOB of data held by Object Storage; can be in any
        format.</para>
      </glossdef>
    </glossentry>

    <glossentry>
      <glossterm>object auditor</glossterm>
      <indexterm class="singular">
          <primary>objects</primary>

          <secondary>object auditors</secondary>
        </indexterm>

      <glossdef>
        <para>Opens all objects for an object server and verifies the MD5
        hash, size, and metadata for each object.</para>
      </glossdef>
    </glossentry>

    <glossentry>
      <glossterm>object expiration</glossterm>
      <indexterm class="singular">
          <primary>objects</primary>

          <secondary>object expiration</secondary>
        </indexterm>

      <glossdef>
        <para>A configurable option within Object Storage to automatically
        delete objects after a specified amount of time has passed or a
        certain date is reached.</para>
      </glossdef>
    </glossentry>

    <glossentry>
      <glossterm>object hash</glossterm>
      <indexterm class="singular">
          <primary>objects</primary>

          <secondary>object hash</secondary>
        </indexterm>

      <glossdef>
        <para>Uniquely ID for an Object Storage object.</para>
      </glossdef>
    </glossentry>

    <glossentry>
      <glossterm>object path hash</glossterm>
      <indexterm class="singular">
          <primary>objects</primary>

          <secondary>object path hash</secondary>
        </indexterm>

      <glossdef>
        <para>Used by Object Storage to determine the location of an object in
        the ring. Maps objects to partitions.</para>
      </glossdef>
    </glossentry>

    <glossentry>
      <glossterm>object replicator</glossterm>
      <indexterm class="singular">
          <primary>objects</primary>

          <secondary>object replicators</secondary>
        </indexterm>

      <glossdef>
        <para>An Object Storage component that copies an object to remote
        partitions for fault tolerance.</para>
      </glossdef>
    </glossentry>

    <glossentry>
      <glossterm>object server</glossterm>
      <indexterm class="singular">
          <primary>objects</primary>

          <secondary>object servers</secondary>
        </indexterm>

      <glossdef>
        <para>An Object Storage component that is responsible for managing
        objects.</para>
      </glossdef>
    </glossentry>

    <glossentry>
      <glossterm>Object Storage</glossterm>

      <glossdef>
        <para>The OpenStack core project that provides eventually consistent
        and redundant storage and retrieval of fixed digital content. The
        project name of OpenStack Object Storage is swift.</para>
      </glossdef>
    </glossentry>

    <glossentry>
      <glossterm>Object Storage API</glossterm>
      <indexterm class="singular">
          <primary>swift</primary>

          <secondary>Object Storage API</secondary>
        </indexterm>
      <indexterm class="singular">
          <primary>Object Storage</primary>

          <secondary>Object Storage API</secondary>
        </indexterm>

      <glossdef>
        <para>API used to access OpenStack Object Storage.</para>
      </glossdef>
    </glossentry>

    <glossentry>
      <glossterm>Object Storage Device (OSD)</glossterm>
      <indexterm class="singular">
          <primary>Object Storage</primary>

          <secondary>Object Storage Device (OSD)</secondary>
        </indexterm>

      <glossdef>
        <para>The Ceph storage daemon.</para>
      </glossdef>
    </glossentry>

    <glossentry>
      <glossterm>object versioning</glossterm>
      <indexterm class="singular">
          <primary>objects</primary>

          <secondary>object versioning</secondary>
        </indexterm>

      <glossdef>
        <para>Allows a user to set a flag on an Object Storage container so
        that all objects within the container are versioned.</para>
      </glossdef>
    </glossentry>

    <glossentry>
      <glossterm>Oldie</glossterm>
      <indexterm class="singular">
          <primary>Oldie</primary>
        </indexterm>

      <glossdef>
        <para>Term for an Object Storage process that runs for a long time.
        Can indicate a hung process.</para>
      </glossdef>
    </glossentry>

    <glossentry>
      <glossterm>Open Cloud Computing Interface (OCCI)</glossterm>
      <indexterm
          class="singular">
          <primary>Open Cloud Computing Interface (OCCI)</primary>
        </indexterm>

      <glossdef>
        <para>A standardized interface for managing compute, data, and network
        resources, currently unsupported in OpenStack.</para>
      </glossdef>
    </glossentry>

    <glossentry>
      <glossterm>Open Virtualization Format (OVF)</glossterm>
      <indexterm class="singular">
          <primary>Open Virtualization Format (OVF)</primary>
        </indexterm>

      <glossdef>
        <para>Standard for packaging VM images. Supported in OpenStack.</para>
      </glossdef>
    </glossentry>

    <glossentry>
      <glossterm>Open vSwitch</glossterm>
      <indexterm class="singular">
          <primary>Open vSwitch</primary>
        </indexterm>

      <glossdef>
        <para>
          Open vSwitch is a production quality, multilayer virtual
          switch licensed under the open source Apache 2.0 license. It
          is designed to enable massive network automation through
          programmatic extension, while still supporting standard
          management interfaces and protocols (for example NetFlow,
          sFlow, SPAN, RSPAN, CLI, LACP, 802.1ag).
        </para>
      </glossdef>
    </glossentry>

    <glossentry>
      <glossterm>Open vSwitch neutron plug-in</glossterm>
      <indexterm class="singular">
          <primary>Open vSwitch</primary>

          <secondary>neutron plug-in for</secondary>
        </indexterm>

      <glossdef>
        <para>Provides support for Open vSwitch in Networking.</para>
      </glossdef>
    </glossentry>

    <glossentry>
      <glossterm>OpenLDAP</glossterm>
      <indexterm class="singular">
          <primary>OpenLDAP</primary>
        </indexterm>

      <glossdef>
        <para>An open source LDAP server. Supported by both Compute and
        Identity Service.</para>
      </glossdef>
    </glossentry>

    <glossentry>
      <glossterm>OpenStack</glossterm>
      <indexterm class="singular">
          <primary>OpenStack</primary>

          <secondary>basics of</secondary>
        </indexterm>

      <glossdef>
        <para>OpenStack is a cloud operating system that controls large pools
        of compute, storage, and networking resources throughout a data
        center, all managed through a dashboard that gives administrators
        control while empowering their users to provision resources through a
        web interface. OpenStack is an open source project licensed under the
        Apache License 2.0.</para>
      </glossdef>
    </glossentry>

    <glossentry>
      <glossterm>OpenStack code name</glossterm>
      <indexterm class="singular">
          <primary>OpenStack</primary>
          <secondary>code name</secondary>
        </indexterm>

      <glossdef>
        <para>
          Each OpenStack release has a code name. Code names ascend in
          alphabetical order: Austin, Bexar, Cactus, Diablo, Essex,
          Folsom, Grizzly, Havana, Icehouse, Juno, and Kilo. Code names are
          cities or counties near where the corresponding OpenStack
          design summit took place. An exception, called the Waldon
          exception, is granted to elements of the state flag that
          sound especially cool. Code names are chosen by popular
          vote.
        </para>
      </glossdef>
    </glossentry>

    <glossentry>
      <glossterm>openSUSE</glossterm>
      <indexterm class="singular">
          <primary>openSUSE</primary>
        </indexterm>

      <glossdef>
        <para>A Linux distribution that is compatible with OpenStack.</para>
      </glossdef>
    </glossentry>

    <glossentry>
      <glossterm>operator</glossterm>
      <indexterm class="singular">
          <primary>operator</primary>
        </indexterm>

      <glossdef>
        <para>The person responsible for planning and maintaining an OpenStack
        installation.</para>
      </glossdef>
    </glossentry>

    <glossentry>
      <glossterm>Orchestration</glossterm>
      <indexterm class="singular">
          <primary>Orchestration</primary>
        </indexterm>

      <glossdef>
        <para>An integrated project that orchestrates multiple cloud
        applications for OpenStack. The project name of Orchestration is
        heat.</para>
      </glossdef>
    </glossentry>

    <glossentry>
      <glossterm>orphan</glossterm>
      <indexterm class="singular">
          <primary>orphans</primary>
        </indexterm>

      <glossdef>
        <para>In the context of Object Storage, this is a process that is not
        terminated after an upgrade, restart, or reload of the service.</para>
      </glossdef>
    </glossentry>
  </glossdiv>

  <!-- .P. -->

  <glossdiv>
    <title>P</title>

    <glossentry>
      <glossterm>parent cell</glossterm>
      <indexterm class="singular">
          <primary>cells</primary>

          <secondary>parent cells</secondary>
        </indexterm>
      <indexterm class="singular">
          <primary>parent cells</primary>
        </indexterm>

      <glossdef>
        <para>If a requested resource, such as CPU time, disk storage, or
        memory, is not available in the parent cell, the request is forwarded
        to associated child cells.</para>
      </glossdef>
    </glossentry>

    <glossentry>
      <glossterm>partition</glossterm>
      <indexterm class="singular">
          <primary>partitions</primary>

          <secondary>definition of</secondary>
        </indexterm>

      <glossdef>
        <para>A unit of storage within Object Storage used to store objects.
        It exists on top of devices and is replicated for fault
        tolerance.</para>
      </glossdef>
    </glossentry>

    <glossentry>
      <glossterm>partition index</glossterm>
      <indexterm class="singular">
          <primary>partitions</primary>

          <secondary>partition index</secondary>
        </indexterm>

      <glossdef>
        <para>Contains the locations of all Object Storage partitions within
        the ring.</para>
      </glossdef>
    </glossentry>

    <glossentry>
      <glossterm>partition shift value</glossterm>
      <indexterm class="singular">
          <primary>partitions</primary>

          <secondary>partition index value</secondary>
        </indexterm>

      <glossdef>
        <para>Used by Object Storage to determine which partition data should
        reside on.</para>
      </glossdef>
    </glossentry>

    <glossentry>
      <glossterm>path MTU discovery (PMTUD)</glossterm>
      <indexterm class="singular">
        <primary>path MTU discovery (PMTUD)</primary>
      </indexterm>

      <glossdef>
        <para>Mechanism in IP networks to detect end-to-end MTU and adjust
          packet size accordingly.</para>
      </glossdef>
    </glossentry>

    <glossentry>
      <glossterm>pause</glossterm>
      <indexterm class="singular">
          <primary>pause</primary>
        </indexterm>

      <glossdef>
        <para>A VM state where no changes occur (no changes in memory, network
        communications stop, etc); the VM is frozen but not shut down.</para>
      </glossdef>
    </glossentry>

    <glossentry>
      <glossterm>PCI passthrough</glossterm>
      <indexterm class="singular">
          <primary>PCI passthrough</primary>
        </indexterm>

      <glossdef>
        <para>Gives guest VMs exclusive access to a PCI device. Currently
        supported in OpenStack Havana and later releases.</para>
      </glossdef>
    </glossentry>

    <glossentry>
      <glossterm>persistent message</glossterm>
      <indexterm class="singular">
          <primary>messages</primary>

          <secondary>persistent messages</secondary>
        </indexterm>
      <indexterm class="singular">
          <primary>persistent messages</primary>
        </indexterm>

      <glossdef>
        <para>A message that is stored both in memory and on disk. The message
        is not lost after a failure or restart.</para>
      </glossdef>
    </glossentry>

    <glossentry>
      <glossterm>persistent volume</glossterm>
      <indexterm class="singular">
          <primary>persistent volume</primary>
        </indexterm>

      <glossdef>
        <para>Changes to these types of disk volumes are saved.</para>
      </glossdef>
    </glossentry>

    <glossentry>
      <glossterm>personality file</glossterm>
      <indexterm class="singular">
          <primary>personality file</primary>
        </indexterm>

      <glossdef>
        <para>A file used to customize a Compute instance. It can be used to
        inject SSH keys or a specific network configuration.</para>
      </glossdef>
    </glossentry>

    <glossentry>
      <glossterm>Platform-as-a-Service (PaaS)</glossterm>
      <indexterm class="singular">
          <primary>Platform-as-a-Service (PaaS)</primary>
        </indexterm>

      <glossdef>
        <para>Provides to the consumer the ability to deploy applications
        through a programming language or tools supported by the cloud
        platform provider. An example of Platform-as-a-Service is an
        Eclipse/Java programming platform provided with no downloads
        required.</para>
      </glossdef>
    </glossentry>

    <glossentry>
      <glossterm>plug-in</glossterm>
      <indexterm class="singular">
          <primary>plug-ins, definition of</primary>
        </indexterm>

      <glossdef>
        <para>Software component providing the actual implementation for
        Networking APIs, or for Compute APIs, depending on the context.</para>
      </glossdef>
    </glossentry>

    <glossentry>
      <glossterm>policy service</glossterm>
      <indexterm class="singular">
          <primary>policy service</primary>
        </indexterm>

      <glossdef>
        <para>Component of Identity Service that provides a rule-management
        interface and a rule-based authorization engine.</para>
      </glossdef>
    </glossentry>

    <glossentry>
      <glossterm>pool</glossterm>
      <indexterm class="singular">
          <primary>pool</primary>
        </indexterm>

      <glossdef>
        <para>A logical set of devices, such as web servers, that you
        group together to receive and process traffic. The load
        balancing function chooses which member of the pool handles
        the new requests or connections received on the VIP
        address. Each VIP has one pool.</para>
      </glossdef>
    </glossentry>

    <glossentry>
      <glossterm>pool member</glossterm>
      <indexterm class="singular">
          <primary>pool member</primary>
        </indexterm>

      <glossdef>
        <para>An application that runs on the back-end server in a
        load-balancing system.</para>
      </glossdef>
    </glossentry>

    <glossentry>
      <glossterm>port</glossterm>
      <indexterm class="singular">
          <primary>ports</primary>

          <secondary>definition of</secondary>
        </indexterm>

      <glossdef>
        <para>A virtual network port within Networking; VIFs / vNICs are
        connected to a port.</para>
      </glossdef>
    </glossentry>

    <glossentry>
      <glossterm>port UUID</glossterm>
      <indexterm class="singular">
          <primary>ports</primary>

          <secondary>port UUID</secondary>
        </indexterm>

      <glossdef>
        <para>Unique ID for a Networking port.</para>
      </glossdef>
    </glossentry>

    <glossentry>
      <glossterm>preseed</glossterm>
      <indexterm class="singular">
          <primary>preseed, definition of</primary>
        </indexterm>

      <glossdef>
        <para>A tool to automate system configuration and installation on
        Debian-based Linux distributions.</para>
      </glossdef>
    </glossentry>

    <glossentry>
      <glossterm>private image</glossterm>
      <indexterm class="singular">
          <primary>private image</primary>
        </indexterm>

      <glossdef>
        <para>An Image Service VM image that is only available to specified
        tenants.</para>
      </glossdef>
    </glossentry>

    <glossentry>
      <glossterm>private IP address</glossterm>
      <indexterm class="singular">
          <primary>IP addresses</primary>

          <secondary>private</secondary>
        </indexterm>
      <indexterm class="singular">
          <primary>private IP address</primary>
        </indexterm>

      <glossdef>
        <para>An IP address used for management and administration, not
        available to the public Internet.</para>
      </glossdef>
    </glossentry>

    <glossentry>
      <glossterm>private network</glossterm>
      <indexterm class="singular">
          <primary>networks</primary>

          <secondary>private networks</secondary>
        </indexterm>
      <indexterm class="singular">
          <primary>private networks</primary>
        </indexterm>

      <glossdef>
        <para>The Network Controller provides virtual networks to enable
        compute servers to interact with each other and with the public
        network. All machines must have a public and private network
        interface. A private network interface can be a flat or VLAN network
        interface. A flat network interface is controlled by the
        flat_interface with flat managers. A VLAN network interface is
        controlled by the <literal>vlan_interface</literal> option with VLAN
        managers.</para>
      </glossdef>
    </glossentry>

    <glossentry>
      <glossterm>project</glossterm>
      <indexterm class="singular">
          <primary>projects</primary>

          <secondary>definition of</secondary>
        </indexterm>

      <glossdef>
        <para>A logical grouping of users within Compute; defines quotas and
        access to VM <phrase role="keep-together">images</phrase>.</para>
      </glossdef>
    </glossentry>

    <glossentry>
      <glossterm>project ID</glossterm>
      <indexterm class="singular">
          <primary>projects</primary>

          <secondary>project ID</secondary>
        </indexterm>

      <glossdef>
        <para>User-defined alphanumeric string in Compute; the name of a
        project.</para>
      </glossdef>
    </glossentry>

    <glossentry>
      <glossterm>project VPN</glossterm>
      <indexterm class="singular">
          <primary>projects</primary>

          <secondary>project VPN</secondary>
        </indexterm>

      <glossdef>
        <para>Alternative term for a cloudpipe.</para>
      </glossdef>
    </glossentry>

    <glossentry>
      <glossterm>promiscuous mode</glossterm>
      <indexterm class="singular">
          <primary>promiscuous mode</primary>
        </indexterm>

      <glossdef>
        <para>Causes the network interface to pass all traffic it
        receives to the host rather than passing only the frames
        addressed to it.</para>
      </glossdef>
    </glossentry>

    <glossentry>
      <glossterm>protected property</glossterm>
      <indexterm class="singular">
          <primary>protected property</primary>
        </indexterm>

      <glossdef>
        <para>Generally, extra properties on an Image Service image to
        which only cloud administrators have access. Limits which user
        roles can perform CRUD operations on that property. The cloud
        administrator can configure any image property as
        protected.</para>
      </glossdef>
    </glossentry>

    <glossentry>
      <glossterm>provider</glossterm>
      <indexterm class="singular">
          <primary>provider</primary>
        </indexterm>

      <glossdef>
        <para>An administrator who has access to all hosts and
        instances.</para>
      </glossdef>
    </glossentry>

    <glossentry>
      <glossterm>proxy node</glossterm>
      <indexterm class="singular">
          <primary>nodes</primary>

          <secondary>proxy nodes</secondary>
        </indexterm>
      <indexterm class="singular">
          <primary>proxy nodes</primary>
        </indexterm>

      <glossdef>
        <para>A node that provides the Object Storage proxy service.</para>
      </glossdef>
    </glossentry>

    <glossentry>
      <glossterm>proxy server</glossterm>
      <indexterm class="singular">
          <primary>servers</primary>

          <secondary>proxy servers</secondary>
        </indexterm>
      <indexterm class="singular">
          <primary>proxy servers</primary>
        </indexterm>

      <glossdef>
        <para>Users of Object Storage interact with the service through the
        proxy server, which in turn looks up the location of the requested
        data within the ring and returns the results to the user.</para>
      </glossdef>
    </glossentry>

    <glossentry>
      <glossterm>public API</glossterm>
      <indexterm class="singular">
          <primary>API (application programming interface)</primary>

          <secondary>public APIs</secondary>
        </indexterm>
      <indexterm class="singular">
          <primary>public API</primary>
        </indexterm>

      <glossdef>
        <para>An API endpoint used for both service-to-service communication
        and end-user interactions.</para>
      </glossdef>
    </glossentry>

    <glossentry>
      <glossterm>public image</glossterm>
      <indexterm class="singular">
          <primary>Image Service</primary>

          <secondary>public images</secondary>
        </indexterm>
      <indexterm class="singular">
          <primary>public image</primary>
        </indexterm>

      <glossdef>
        <para>An Image Service VM image that is available to all
        tenants.</para>
      </glossdef>
    </glossentry>

    <glossentry>
      <glossterm>public IP address</glossterm>
      <indexterm class="singular">
          <primary>IP addresses</primary>

          <secondary>public</secondary>
        </indexterm>
      <indexterm class="singular">
          <primary>public IP address</primary>
        </indexterm>

      <glossdef>
        <para>An IP address that is accessible to end-users.</para>
      </glossdef>
    </glossentry>

    <glossentry>
      <glossterm>public key authentication</glossterm>
      <indexterm class="singular">
          <primary>public key authentication</primary>
        </indexterm>

      <glossdef>
        <para>Authentication method that uses keys rather than
        passwords.</para>
      </glossdef>
    </glossentry>

    <glossentry>
      <glossterm>public network</glossterm>
      <indexterm class="singular">
          <primary>networks</primary>

          <secondary>public</secondary>
        </indexterm>
      <indexterm class="singular">
          <primary>public network</primary>
        </indexterm>

      <glossdef>
        <para>The Network Controller provides virtual networks to enable
        compute servers to interact with each other and with the public
        network. All machines must have a public and private network
        interface. The public network interface is controlled by the
        <literal>public_interface</literal> option.</para>
      </glossdef>
    </glossentry>

    <glossentry>
      <glossterm>Puppet</glossterm>
      <indexterm class="singular">
          <primary>Puppet</primary>
        </indexterm>

      <glossdef>
        <para>An operating system configuration-management tool supported by
        OpenStack.</para>
      </glossdef>
    </glossentry>

    <glossentry>
      <glossterm>Python</glossterm>
      <indexterm class="singular">
          <primary>Python</primary>
        </indexterm>

      <glossdef>
        <para>Programming language used extensively in OpenStack.</para>
      </glossdef>
    </glossentry>
  </glossdiv>

  <!-- .Q. -->

  <glossdiv>
    <title>Q</title>

    <glossentry>
      <glossterm>QEMU Copy On Write 2 (QCOW2)</glossterm>
      <indexterm class="singular">
          <primary>QEMU Copy On Write 2 (QCOW2)</primary>
        </indexterm>

      <glossdef>
        <para>One of the VM image disk formats supported by Image
        Service.</para>
      </glossdef>
    </glossentry>

    <glossentry>
      <glossterm>Qpid</glossterm>
      <indexterm class="singular">
          <primary>Qpid</primary>
        </indexterm>

      <glossdef>
        <para>Message queue software supported by OpenStack; an alternative to
        RabbitMQ.</para>
      </glossdef>
    </glossentry>

    <glossentry>
      <glossterm>quarantine</glossterm>
      <indexterm class="singular">
          <primary>quarantine</primary>
        </indexterm>

      <glossdef>
        <para>If Object Storage finds objects, containers, or accounts that
        are corrupt, they are placed in this state, are not replicated, cannot
        be read by clients, and a correct copy is re-replicated.</para>
      </glossdef>
    </glossentry>

    <glossentry>
      <glossterm>Quick EMUlator (QEMU)</glossterm>
      <indexterm class="singular">
          <primary>Quick EMUlator (QEMU)</primary>
        </indexterm>

      <glossdef>
        <para>QEMU is a generic and open source machine emulator and
        virtualizer.</para>

        <para>One of the hypervisors supported by OpenStack, generally used
        for development purposes.</para>
      </glossdef>
    </glossentry>

    <glossentry>
      <glossterm>quota</glossterm>
      <indexterm class="singular">
          <primary>quotas</primary>
        </indexterm>

      <glossdef>
        <para>In Compute and Block Storage, the ability to set resource limits
        on a per-project <phrase role="keep-together">basis</phrase>.</para>
      </glossdef>
    </glossentry>
  </glossdiv>

  <!-- .R. -->

  <glossdiv>
    <title>R</title>

    <glossentry>
      <glossterm>RabbitMQ</glossterm>
      <indexterm class="singular">
          <primary>RabbitMQ</primary>
        </indexterm>

      <glossdef>
        <para>The default message queue software used by OpenStack.</para>
      </glossdef>
    </glossentry>

    <glossentry>
      <glossterm>Rackspace Cloud Files</glossterm>
      <indexterm class="singular">
          <primary>Rackspace Cloud Files</primary>
        </indexterm>

      <glossdef>
        <para>Released as open source by Rackspace in 2010; the basis for
        Object Storage.</para>
      </glossdef>
    </glossentry>

    <glossentry>
      <glossterm>RADOS Block Device (RBD)</glossterm>
      <indexterm class="singular">
          <primary>RADOS Block Device (RBD)</primary>
        </indexterm>

      <glossdef>
        <para>Ceph component that enables a Linux block device to be striped
        over multiple distributed data stores.</para>
      </glossdef>
    </glossentry>

    <glossentry>
      <glossterm>radvd</glossterm>
      <indexterm class="singular">
          <primary>radvd</primary>
        </indexterm>

      <glossdef>
        <para>The router advertisement daemon, used by the Compute VLAN
        manager and FlatDHCP manager to provide routing services for VM
        instances.</para>
      </glossdef>
    </glossentry>

    <glossentry>
      <glossterm>RAM filter</glossterm>
      <indexterm class="singular">
          <primary>RAM filter</primary>
        </indexterm>

      <glossdef>
        <para>The Compute setting that enables or disables RAM
        overcommitment.</para>
      </glossdef>
    </glossentry>

    <glossentry>
      <glossterm>RAM overcommit</glossterm>
      <indexterm class="singular">
          <primary>RAM overcommit</primary>
        </indexterm>

      <glossdef>
        <para>The ability to start new VM instances based on the actual memory
        usage of a host, as opposed to basing the decision on the amount of
        RAM each running instance thinks it has available. Also known as
        memory overcommit.</para>
      </glossdef>
    </glossentry>

    <glossentry>
      <glossterm>rate limit</glossterm>
      <indexterm class="singular">
          <primary>rate limits</primary>
        </indexterm>

      <glossdef>
        <para>Configurable option within Object Storage to limit database
        writes on a per-account and/or per-container basis.</para>
      </glossdef>
    </glossentry>

    <glossentry>
      <glossterm>raw</glossterm>
      <indexterm class="singular">
          <primary>raw format</primary>
        </indexterm>

      <glossdef>
        <para>One of the VM image disk formats supported by Image Service; an
        unstructured disk image.</para>
      </glossdef>
    </glossentry>

    <glossentry>
      <glossterm>rebalance</glossterm>
      <indexterm class="singular">
          <primary>rebalancing</primary>
        </indexterm>

      <glossdef>
        <para>The process of distributing Object Storage partitions across all
        drives in the ring; used during initial ring creation and after ring
        reconfiguration.</para>
      </glossdef>
    </glossentry>

    <glossentry>
      <glossterm>reboot</glossterm>
      <indexterm class="singular">
          <primary>reboot</primary>

          <secondary>hard vs. soft</secondary>
        </indexterm>

      <glossdef>
        <para>Either a soft or hard reboot of a server. With a soft reboot,
        the operating system is signaled to restart, which enables a graceful
        shutdown of all processes. A hard reboot is the equivalent of power
        cycling the server. The virtualization platform should ensure that the
        reboot action has completed successfully, even in cases in which the
        underlying domain/VM is paused or halted/stopped.</para>
      </glossdef>
    </glossentry>

    <glossentry>
      <glossterm>rebuild</glossterm>
      <indexterm class="singular">
          <primary>rebuilding</primary>
        </indexterm>

      <glossdef>
        <para>Removes all data on the server and replaces it with the
        specified image. Server ID and IP addresses remain the same.</para>
      </glossdef>
    </glossentry>

    <glossentry>
      <glossterm>Recon</glossterm>
      <indexterm class="singular">
          <primary>Recon</primary>
        </indexterm>

      <glossdef>
        <para>An Object Storage component that collects metrics.</para>
      </glossdef>
    </glossentry>

    <glossentry>
      <glossterm>record</glossterm>
      <indexterm class="singular">
          <primary>records</primary>

          <secondary>basics of</secondary>
        </indexterm>

      <glossdef>
        <para>Belongs to a particular domain and is used to specify
        information about the <phrase role="keep-together">domain</phrase>.
        There are several types of DNS records. Each record type contains
        particular information used to describe the purpose of that record.
        Examples include mail exchange (MX) records, which specify the mail
        server for a particular domain; and name server (NS) records, which
        specify the authoritative name servers for a domain.</para>
      </glossdef>
    </glossentry>

    <glossentry>
      <glossterm>record ID</glossterm>
      <indexterm class="singular">
          <primary>records</primary>

          <secondary>record IDs</secondary>
        </indexterm>

      <glossdef>
        <para>A number within a database that is incremented each time a
        change is made. Used by Object Storage when replicating.</para>
      </glossdef>
    </glossentry>

    <glossentry>
      <glossterm>Red Hat Enterprise Linux (RHEL)</glossterm>
      <indexterm class="singular">
          <primary>Red Hat Enterprise Linux (RHEL)</primary>
        </indexterm>

      <glossdef>
        <para>A Linux distribution that is compatible with OpenStack.</para>
      </glossdef>
    </glossentry>

    <glossentry>
      <glossterm>reference architecture</glossterm>
      <indexterm class="singular">
          <primary>reference architecture</primary>
        </indexterm>

      <glossdef>
        <para>A recommended architecture for an OpenStack cloud.</para>
      </glossdef>
    </glossentry>

    <glossentry>
      <glossterm>region</glossterm>
      <indexterm class="singular">
          <primary>region</primary>
        </indexterm>

      <glossdef>
        <para>A discrete OpenStack environment with dedicated API endpoints
        that typically shares only the Identity Service (keystone) with other
        regions.</para>
      </glossdef>
    </glossentry>

    <glossentry>
      <glossterm>registry</glossterm>
      <indexterm class="singular">
          <primary>registry</primary>

          <see>under Image Service</see>
        </indexterm>

      <glossdef>
        <para>Alternative term for the Image Service registry.</para>
      </glossdef>
    </glossentry>

    <glossentry>
      <glossterm>registry server</glossterm>
      <indexterm class="singular">
          <primary>servers</primary>

          <secondary>registry servers</secondary>
        </indexterm>
      <indexterm class="singular">
          <primary>registry servers</primary>
        </indexterm>

      <glossdef>
        <para>An Image Service that provides VM image metadata information to
        clients.</para>
      </glossdef>
    </glossentry>

    <glossentry>
      <glossterm>Reliable, Autonomic Distributed Object Store
      (RADOS)</glossterm>
      <indexterm class="singular">
          <primary>Reliable, Autonomic Distributed Object Store
          (RADOS)</primary>
        </indexterm>

      <glossdef>
        <para>A collection of components that provides object storage within
        Ceph. Similar to OpenStack Object Storage.</para>
      </glossdef>
    </glossentry>

    <glossentry>
      <glossterm>Remote Procedure Call (RPC)</glossterm>
      <indexterm class="singular">
          <primary>Remote Procedure Call (RPC)</primary>
        </indexterm>

      <glossdef>
        <para>The method used by the Compute RabbitMQ for intra-service
        communications.</para>
      </glossdef>
    </glossentry>

    <glossentry>
      <glossterm>replica</glossterm>
      <indexterm class="singular">
          <primary>replication</primary>

          <secondary>definition of</secondary>
        </indexterm>

      <glossdef>
        <para>Provides data redundancy and fault tolerance by creating copies
        of Object Storage objects, accounts, and containers so that they are
        not lost when the underlying storage fails.</para>
      </glossdef>
    </glossentry>

    <glossentry>
      <glossterm>replica count</glossterm>
      <indexterm class="singular">
          <primary>replication</primary>

          <secondary>replica count</secondary>
        </indexterm>

      <glossdef>
        <para>The number of replicas of the data in an Object Storage
        ring.</para>
      </glossdef>
    </glossentry>

    <glossentry>
      <glossterm>replication</glossterm>

      <glossdef>
        <para>The process of copying data to a separate physical device for
        fault tolerance and performance.</para>
      </glossdef>
    </glossentry>

    <glossentry>
      <glossterm>replicator</glossterm>
      <indexterm class="singular">
          <primary>replication</primary>

          <secondary>replicators</secondary>
        </indexterm>

      <glossdef>
        <para>The Object Storage back-end process that creates and manages
        object replicas.</para>
      </glossdef>
    </glossentry>

    <glossentry>
      <glossterm>request ID</glossterm>
      <indexterm class="singular">
          <primary>request IDs</primary>
        </indexterm>

      <glossdef>
        <para>Unique ID assigned to each request sent to Compute.</para>
      </glossdef>
    </glossentry>

    <glossentry>
      <glossterm>rescue image</glossterm>
      <indexterm class="singular">
          <primary>rescue images</primary>
        </indexterm>

      <glossdef>
        <para>A special type of VM image that is booted when an instance is
        placed into rescue mode. Allows an administrator to mount the file
        systems for an instance to correct the problem.</para>
      </glossdef>
    </glossentry>

    <glossentry>
      <glossterm>resize</glossterm>
      <indexterm class="singular">
          <primary>resizing</primary>
        </indexterm>

      <glossdef>
        <para>Converts an existing server to a different flavor, which scales
        the server up or down. The original server is saved to enable rollback
        if a problem occurs. All resizes must be tested and explicitly
        confirmed, at which time the original server is removed.</para>
      </glossdef>
    </glossentry>

    <glossentry>
      <glossterm>RESTful</glossterm>
      <indexterm class="singular">
          <primary>RESTful web services</primary>
        </indexterm>

      <glossdef>
        <para>A kind of web service API that uses REST, or Representational
        State Transfer. REST is the style of architecture for hypermedia
        systems that is used for the World Wide Web.</para>
      </glossdef>
    </glossentry>

    <glossentry>
      <glossterm>ring</glossterm>
      <indexterm class="singular">
          <primary>rings</primary>

          <secondary>definition of</secondary>
        </indexterm>

      <glossdef>
        <para>An entity that maps Object Storage data to partitions. A
        separate ring exists for each service, such as account, object, and
        container.</para>
      </glossdef>
    </glossentry>

    <glossentry>
      <glossterm>ring builder</glossterm>
      <indexterm class="singular">
          <primary>rings</primary>

          <secondary>ring builders</secondary>
        </indexterm>

      <glossdef>
        <para>Builds and manages rings within Object Storage, assigns
        partitions to devices, and pushes the configuration to other storage
        nodes.</para>
      </glossdef>
    </glossentry>

    <glossentry>
      <glossterm>Role Based Access Control (RBAC)</glossterm>
      <indexterm class="singular">
          <primary>Role Based Access Control (RBAC)</primary>
        </indexterm>

      <glossdef>
        <para>Provides a predefined list of actions that the user can perform,
        such as start or stop VMs, reset passwords, and so on. Supported in
        both Identity Service and Compute and can be configured using the
        horizon dashboard.</para>
      </glossdef>
    </glossentry>

    <glossentry>
      <glossterm>role</glossterm>
      <indexterm class="singular">
          <primary>roles</primary>

          <secondary>definition of</secondary>
        </indexterm>

      <glossdef>
        <para>A personality that a user assumes to perform a specific set of
        operations. A role includes a set of rights and privileges. A user
        assuming that role inherits those rights and privileges.</para>
      </glossdef>
    </glossentry>

    <glossentry>
      <glossterm>role ID</glossterm>
      <indexterm class="singular">
          <primary>roles</primary>

          <secondary>role ID</secondary>
        </indexterm>

      <glossdef>
        <para>Alphanumeric ID assigned to each Identity Service role.</para>
      </glossdef>
    </glossentry>

    <glossentry>
      <glossterm>rootwrap</glossterm>
      <indexterm class="singular">
          <primary>rootwrap</primary>
        </indexterm>

      <glossdef>
        <para>A feature of Compute that allows the unprivileged "nova" user to
        run a specified list of commands as the Linux root user.</para>
      </glossdef>
    </glossentry>

    <glossentry>
      <glossterm>round-robin scheduler</glossterm>
      <indexterm class="singular">
          <primary>schedulers</primary>

          <secondary>round-robin</secondary>
        </indexterm>
      <indexterm class="singular">
          <primary>round-robin scheduler</primary>
        </indexterm>

      <glossdef>
        <para>Type of Compute scheduler that evenly distributes instances
        among available hosts.</para>
      </glossdef>
    </glossentry>

    <glossentry>
      <glossterm>router</glossterm>
      <indexterm class="singular">
          <primary>router</primary>
        </indexterm>

      <glossdef>
        <para>A physical or virtual network device that passes network
        traffic between different networks.</para>
      </glossdef>
    </glossentry>

    <glossentry>
      <glossterm>routing key</glossterm>
      <indexterm class="singular">
          <primary>routing keys</primary>
        </indexterm>

      <glossdef>
        <para>The Compute direct exchanges, fanout exchanges, and topic
        exchanges use this key to determine how to process a message;
        processing varies depending on exchange type.</para>
      </glossdef>
    </glossentry>

    <glossentry>
      <glossterm>RPC driver</glossterm>
      <indexterm class="singular">
          <primary>drivers</primary>

          <secondary>RPC drivers</secondary>
        </indexterm>
      <indexterm class="singular">
          <primary>RPC drivers</primary>
        </indexterm>

      <glossdef>
        <para>Modular system that allows the underlying message queue software
        of Compute to be changed. For example, from RabbitMQ to ZeroMQ or
        Qpid.</para>
      </glossdef>
    </glossentry>

    <glossentry>
      <glossterm>rsync</glossterm>
      <indexterm class="singular">
          <primary>rsync</primary>
        </indexterm>

      <glossdef>
        <para>Used by Object Storage to push object replicas.</para>
      </glossdef>
    </glossentry>

    <glossentry>
      <glossterm>RXTX cap</glossterm>
      <indexterm class="singular">
          <primary>RXTX cap/quota</primary>
        </indexterm>

      <glossdef>
        <para>Absolute limit on the amount of network traffic a Compute VM
        instance can send and receive.</para>
      </glossdef>
    </glossentry>

    <glossentry>
      <glossterm>RXTX quota</glossterm>

      <glossdef>
        <para>Soft limit on the amount of network traffic a Compute VM
        instance can send and receive.</para>
      </glossdef>
    </glossentry>

    <glossentry>
      <glossterm>Ryu neutron plug-in</glossterm>
      <indexterm class="singular">
          <primary>Ryu neutron plug-in</primary>
        </indexterm>

      <glossdef>
        <para>Enables the Ryu network operating system to function as a
        Networking OpenFlow controller.</para>
      </glossdef>
    </glossentry>
  </glossdiv>

  <!-- .S. -->

  <glossdiv>
    <title>S</title>

    <glossentry>
      <glossterm>S3</glossterm>
      <indexterm class="singular">
          <primary>S3 storage service</primary>
        </indexterm>

      <glossdef>
        <para>Object storage service by Amazon; similar in function to Object
        Storage, it can act as a back-end store for Image Service VM <phrase
        role="keep-together">images</phrase>.</para>
      </glossdef>
    </glossentry>

    <glossentry>
      <glossterm>sahara</glossterm>
      <indexterm class="singular">
          <primary>sahara</primary>
        </indexterm>

      <glossdef>
        <para>OpenStack project that provides a scalable data-processing stack
        and associated management interfaces.</para>
      </glossdef>
    </glossentry>

    <glossentry>
      <glossterm>scheduler manager</glossterm>
      <indexterm class="singular">
          <primary>scheduler manager</primary>
        </indexterm>

      <glossdef>
        <para>A Compute component that determines where VM instances should
        start. Uses modular design to support a variety of scheduler
        types.</para>
      </glossdef>
    </glossentry>

    <glossentry>
      <glossterm>scoped token</glossterm>
      <indexterm class="singular">
          <primary>scoped tokens</primary>
        </indexterm>

      <glossdef>
        <para>An Identity Service API access token that is associated with a
        specific tenant.</para>
      </glossdef>
    </glossentry>

    <glossentry>
      <glossterm>scrubber</glossterm>
      <indexterm class="singular">
          <primary>scrubbers</primary>
        </indexterm>

      <glossdef>
        <para>Checks for and deletes unused VMs; the component of Image
        Service that implements delayed delete.</para>
      </glossdef>
    </glossentry>

    <glossentry>
      <glossterm>secret key</glossterm>
      <indexterm class="singular">
          <primary>secret keys</primary>
        </indexterm>

      <glossdef>
        <para>String of text known only by the user; used along with an access
        key to make requests to the Compute API.</para>
      </glossdef>
    </glossentry>

    <glossentry>
      <glossterm>secure shell (SSH)</glossterm>
      <indexterm class="singular">
          <primary>secure shell (SSH)</primary>
        </indexterm>

      <glossdef>
        <para>Open source tool used to access remote hosts through an
        encrypted communications channel, SSH key injection is supported by
        Compute.</para>
      </glossdef>
    </glossentry>

    <glossentry>
      <glossterm>security group</glossterm>
      <indexterm class="singular">
          <primary>security groups</primary>
        </indexterm>

      <glossdef>
        <para>A set of network traffic filtering rules that are applied to a
        Compute instance.</para>
      </glossdef>
    </glossentry>

    <glossentry>
      <glossterm>segmented object</glossterm>
      <indexterm class="singular">
          <primary>objects</primary>

          <secondary>segmented objects</secondary>
        </indexterm>
      <indexterm class="singular">
          <primary>segmented objects</primary>
        </indexterm>

      <glossdef>
        <para>An Object Storage large object that has been broken up into
        pieces. The re-assembled object is called a concatenated
        object.</para>
      </glossdef>
    </glossentry>

    <glossentry>
      <glossterm>server</glossterm>
      <indexterm class="singular">
          <primary>servers</primary>

          <secondary>definition of</secondary>
        </indexterm>

      <glossdef>
        <para>Computer that provides explicit services to the client software
        running on that system, often managing a variety of computer
        operations.</para>

        <para>A server is a VM instance in the Compute system. Flavor and
        image are requisite elements when creating a server.</para>
      </glossdef>
    </glossentry>

    <glossentry>
      <glossterm>server image</glossterm>
      <indexterm class="singular">
          <primary>server image</primary>
        </indexterm>

      <glossdef>
        <para>Alternative term for a VM image.</para>
      </glossdef>
    </glossentry>

    <glossentry>
      <glossterm>server UUID</glossterm>
      <indexterm class="singular">
          <primary>servers</primary>

          <secondary>server UUID</secondary>
        </indexterm>

      <glossdef>
        <para>Unique ID assigned to each guest VM <phrase
        role="keep-together">instance</phrase>.</para>
      </glossdef>
    </glossentry>

    <glossentry>
      <glossterm>service</glossterm>
      <indexterm class="singular">
          <primary>services</primary>

          <secondary>definition of</secondary>
        </indexterm>

      <glossdef>
        <para>An OpenStack service, such as Compute, Object Storage, or Image
        Service. Provides one or more endpoints through which users can access
        resources and perform operations.</para>
      </glossdef>
    </glossentry>

    <glossentry>
      <glossterm>service catalog</glossterm>
      <indexterm class="singular">
          <primary>service catalog</primary>
        </indexterm>

      <glossdef>
        <para>Alternative term for the Identity Service catalog.</para>
      </glossdef>
    </glossentry>

    <glossentry>
      <glossterm>service ID</glossterm>
      <indexterm class="singular">
          <primary>service ID</primary>
        </indexterm>

      <glossdef>
        <para>Unique ID assigned to each service that is available in the
        Identity Service catalog.</para>
      </glossdef>
    </glossentry>

    <glossentry>
      <glossterm>service registration</glossterm>
      <indexterm class="singular">
          <primary>service registration</primary>
        </indexterm>

      <glossdef>
        <para>An Identity Service feature that enables services, such as
        Compute, to automatically register with the catalog.</para>
      </glossdef>
    </glossentry>

    <glossentry>
      <glossterm>service tenant</glossterm>
      <indexterm class="singular">
          <primary>service tenant</primary>
        </indexterm>

      <glossdef>
        <para>Special tenant that contains all services that are listed in the
        catalog.</para>
      </glossdef>
    </glossentry>

    <glossentry>
      <glossterm>service token</glossterm>
      <indexterm class="singular">
          <primary>service token</primary>
        </indexterm>

      <glossdef>
        <para>An administrator-defined token used by Compute to communicate
        securely with the Identity Service.</para>
      </glossdef>
    </glossentry>

    <glossentry>
      <glossterm>session back end</glossterm>
      <indexterm class="singular">
          <primary>sessions</primary>

          <secondary>session back end</secondary>
        </indexterm>

      <glossdef>
        <para>The method of storage used by horizon to track client sessions,
        such as local memory, cookies, a database, or memcached.</para>
      </glossdef>
    </glossentry>

    <glossentry>
      <glossterm>session persistence</glossterm>
      <indexterm class="singular">
          <primary>sessions</primary>

          <secondary>session persistence</secondary>
        </indexterm>

      <glossdef>
        <para>A feature of the load-balancing service. It attempts to force
        subsequent connections to a service to be redirected to the same node
        as long as it is online.</para>
      </glossdef>
    </glossentry>

    <glossentry>
      <glossterm>session storage</glossterm>
      <indexterm class="singular">
          <primary>sessions</primary>

          <secondary>session storage</secondary>
        </indexterm>

      <glossdef>
        <para>A horizon component that stores and tracks client session
        information. Implemented through the Django sessions framework.</para>
      </glossdef>
    </glossentry>

    <glossentry>
      <glossterm>shared IP address</glossterm>
      <indexterm class="singular">
          <primary>IP addresses</primary>

          <secondary>shared</secondary>
        </indexterm>
      <indexterm class="singular">
          <primary>shared IP address</primary>
        </indexterm>

      <glossdef>
        <para>An IP address that can be assigned to a VM instance within the
        shared IP group. Public IP addresses can be shared across multiple
        servers for use in various high-availability scenarios. When an IP
        address is shared to another server, the cloud network restrictions
        are modified to enable each server to listen to and respond on that IP
        address. You can optionally specify that the target server network
        configuration be modified. Shared IP addresses can be used with many
        standard heartbeat facilities, such as keepalive, that monitor for
        failure and manage IP failover.</para>
      </glossdef>
    </glossentry>

    <glossentry>
      <glossterm>shared IP group</glossterm>
      <indexterm class="singular">
          <primary>shared IP groups</primary>
        </indexterm>

      <glossdef>
        <para>A collection of servers that can share IPs with other members of
        the group. Any server in a group can share one or more public IPs with
        any other server in the group. With the exception of the first server
        in a shared IP group, servers must be launched into shared IP groups.
        A server may be a member of only one shared IP group.</para>
      </glossdef>
    </glossentry>

    <glossentry>
      <glossterm>shared storage</glossterm>
      <indexterm class="singular">
          <primary>shared storage</primary>
        </indexterm>

      <glossdef>
        <para>Block storage that is simultaneously accessible by multiple
        clients, for example, NFS.</para>
      </glossdef>
    </glossentry>

    <glossentry>
      <glossterm>Sheepdog</glossterm>
      <indexterm class="singular">
          <primary>Sheepdog</primary>
        </indexterm>

      <glossdef>
        <para>Distributed block storage system for QEMU, supported by
        OpenStack.</para>
      </glossdef>
    </glossentry>

    <glossentry>
      <glossterm>Simple Cloud Identity Management (SCIM)</glossterm>
      <indexterm
          class="singular">
          <primary>Simple Cloud Identity Management (SCIM)</primary>
        </indexterm>

      <glossdef>
        <para>Specification for managing identity in the cloud, currently
        unsupported by OpenStack.</para>
      </glossdef>
    </glossentry>

    <glossentry>
      <glossterm>Single-root I/O Virtualization (SR-IOV)</glossterm>
      <indexterm
          class="singular">
          <primary>Single-root I/O Virtualization (SR-IOV)</primary>
        </indexterm>

      <glossdef>
        <para>A specification that, when implemented by a physical PCIe
        device, enables it to appear as multiple separate PCIe devices. This
        enables multiple virtualized guests to share direct access to the
        physical device, offering improved performance over an equivalent
        virtual device. Currently supported in OpenStack Havana and later
        <phrase role="keep-together">releases</phrase>.</para>
      </glossdef>
    </glossentry>

    <glossentry>
      <glossterm>SmokeStack</glossterm>
      <indexterm class="singular">
          <primary>SmokeStack</primary>
        </indexterm>

      <glossdef>
        <para>Runs automated tests against the core OpenStack API; written in
        Rails.</para>
      </glossdef>
    </glossentry>

    <glossentry>
      <glossterm>snapshot</glossterm>
      <indexterm class="singular">
          <primary>snapshot</primary>
        </indexterm>

      <glossdef>
        <para>A point-in-time copy of an OpenStack storage volume or image.
        Use storage volume snapshots to back up volumes. Use image snapshots
        to back up data, or as "gold" images for additional servers.</para>
      </glossdef>
    </glossentry>

    <glossentry>
      <glossterm>soft reboot</glossterm>
      <indexterm class="singular">
          <primary>reboot</primary>

          <secondary>hard vs. soft</secondary>
        </indexterm>
      <indexterm class="singular">
          <primary>soft reboot</primary>
        </indexterm>

      <glossdef>
        <para>A controlled reboot where a VM instance is properly restarted
        through operating system commands.</para>
      </glossdef>
    </glossentry>

    <glossentry>
      <glossterm>SolidFire Volume Driver</glossterm>
      <indexterm class="singular">
          <primary>SolidFire Volume Driver</primary>
        </indexterm>

      <glossdef>
        <para>The Block Storage driver for the SolidFire iSCSI storage
        appliance.</para>
      </glossdef>
    </glossentry>

    <glossentry>
      <glossterm>SPICE</glossterm>
      <indexterm class="singular">
          <primary>SPICE (Simple Protocol for Independent Computing
          Environments)</primary>
        </indexterm>

      <glossdef>
        <para>The Simple Protocol for Independent Computing Environments
        (SPICE) provides remote desktop access to guest virtual machines. It
        is an alternative to VNC. SPICE is supported by OpenStack.</para>
      </glossdef>
    </glossentry>

    <glossentry>
      <glossterm>spread-first scheduler</glossterm>
      <indexterm class="singular">
          <primary>schedulers</primary>

          <secondary>spread-first</secondary>
        </indexterm>
      <indexterm class="singular">
          <primary>spread-first scheduler</primary>
        </indexterm>

      <glossdef>
        <para>The Compute VM scheduling algorithm that attempts to start a new
        VM on the host with the least amount of load.</para>
      </glossdef>
    </glossentry>

    <glossentry>
      <glossterm>SQL-Alchemy</glossterm>
      <indexterm class="singular">
          <primary>SQL-Alchemy</primary>
        </indexterm>

      <glossdef>
        <para>An open source SQL toolkit for Python, used in OpenStack.</para>
      </glossdef>
    </glossentry>

    <glossentry>
      <glossterm>SQLite</glossterm>
      <indexterm class="singular">
          <primary>SQLite</primary>
        </indexterm>

      <glossdef>
        <para>A lightweight SQL database, used as the default persistent
        storage method in many OpenStack services.</para>
      </glossdef>
    </glossentry>

    <glossentry>
      <glossterm>stack</glossterm>
      <indexterm class="singular">
          <primary>stack</primary>
          <see>Heat Orchestration Template (HOT)</see>
        </indexterm>

      <glossdef>
        <para>A set of OpenStack resources created and managed by the
        Orchestration service according to a given template (either an
        AWS CloudFormation template or a Heat Orchestration
        Template (HOT)).</para>
      </glossdef>
    </glossentry>

    <glossentry>
      <glossterm>StackTach</glossterm>
      <indexterm class="singular">
          <primary>StackTach</primary>
        </indexterm>

      <glossdef>
        <para>Community project that captures Compute AMQP communications;
        useful for debugging.</para>
      </glossdef>
    </glossentry>

    <glossentry>
      <glossterm>static IP address</glossterm>
      <indexterm class="singular">
          <primary>IP addresses</primary>

          <secondary>static</secondary>
        </indexterm>
      <indexterm class="singular">
          <primary>static IP addresses</primary>
        </indexterm>

      <glossdef>
        <para>Alternative term for a fixed IP address.</para>
      </glossdef>
    </glossentry>

    <glossentry>
      <glossterm>StaticWeb</glossterm>
      <indexterm class="singular">
          <primary>StaticWeb</primary>
        </indexterm>

      <glossdef>
        <para>WSGI middleware component of Object Storage that serves
        container data as a static web page.</para>
      </glossdef>
    </glossentry>

    <glossentry>
      <glossterm>storage back end</glossterm>
      <indexterm class="singular">
          <primary>storage back end</primary>
        </indexterm>

      <glossdef>
        <para>The method that a service uses for persistent storage, such as
        iSCSI, NFS, or local disk.</para>
      </glossdef>
    </glossentry>

    <glossentry>
      <glossterm>storage node</glossterm>
      <indexterm class="singular">
          <primary>nodes</primary>

          <secondary>storage nodes</secondary>
        </indexterm>
      <indexterm class="singular">
          <primary>storage node</primary>
        </indexterm>

      <glossdef>
        <para>An Object Storage node that provides container services, account
        services, and object services; controls the account databases,
        container databases, and object storage.</para>
      </glossdef>
    </glossentry>

    <glossentry>
      <glossterm>storage manager</glossterm>
      <indexterm class="singular">
          <primary>storage</primary>

          <secondary>storage manager</secondary>
        </indexterm>

      <glossdef>
        <para>A XenAPI component that provides a pluggable interface to
        support a wide variety of persistent storage back ends.</para>
      </glossdef>
    </glossentry>

    <glossentry>
      <glossterm>storage manager back end</glossterm>
      <indexterm class="singular">
          <primary>storage</primary>

          <secondary>storage manager back end</secondary>
        </indexterm>

      <glossdef>
        <para>A persistent storage method supported by XenAPI, such as iSCSI
        or NFS.</para>
      </glossdef>
    </glossentry>

    <glossentry>
      <glossterm>storage services</glossterm>
      <indexterm class="singular">
          <primary>storage</primary>

          <secondary>storage services</secondary>
        </indexterm>

      <glossdef>
        <para>Collective name for the Object Storage object services,
        container services, and account services.</para>
      </glossdef>
    </glossentry>

    <glossentry>
      <glossterm>strategy</glossterm>
      <indexterm class="singular">
          <primary>strategy</primary>
        </indexterm>

      <glossdef>
        <para>Specifies the authentication source used by Image Service or
        Identity Service.</para>
      </glossdef>
    </glossentry>

    <glossentry>
      <glossterm>subdomain</glossterm>
      <indexterm class="singular">
          <primary>subdomains</primary>
        </indexterm>

      <glossdef>
        <para>A domain within a parent domain. Subdomains cannot be
        registered. Subdomains enable you to delegate domains. Subdomains can
        themselves have subdomains, so third-level, fourth-level, fifth-level,
        and deeper levels of nesting are possible.</para>
      </glossdef>
    </glossentry>

    <glossentry>
      <glossterm>subnet</glossterm>
      <indexterm class="singular">
          <primary>subnet</primary>
        </indexterm>

      <glossdef>
        <para>Logical subdivision of an IP network.</para>
      </glossdef>
    </glossentry>

    <glossentry>
      <glossterm>SUSE Linux Enterprise Server (SLES)</glossterm>
      <indexterm
          class="singular">
          <primary>SUSE Linux Enterprise Server (SLES)</primary>
        </indexterm>

      <glossdef>
        <para>A Linux distribution that is compatible with OpenStack.</para>
      </glossdef>
    </glossentry>

    <glossentry>
      <glossterm>suspend</glossterm>
      <indexterm class="singular">
          <primary>suspend, definition of</primary>
        </indexterm>

      <glossdef>
        <para>Alternative term for a paused VM <phrase
        role="keep-together">instance</phrase>.</para>
      </glossdef>
    </glossentry>

    <glossentry>
      <glossterm>swap</glossterm>
      <indexterm class="singular">
          <primary>swap, definition of</primary>
        </indexterm>

      <glossdef>
        <para>Disk-based virtual memory used by operating systems to provide
        more memory than is actually available on the system.</para>
      </glossdef>
    </glossentry>

    <glossentry>
      <glossterm>swawth</glossterm>
      <indexterm class="singular">
          <primary>swawth</primary>
        </indexterm>

      <glossdef>
        <para>An authentication and authorization service for Object Storage,
        implemented through WSGI middleware; uses Object Storage itself as the
        persistent backing store.</para>
      </glossdef>
    </glossentry>

    <glossentry>
      <glossterm>swift</glossterm>

      <glossdef>
        <para>An OpenStack core project that provides object storage
        services.</para>
      </glossdef>
    </glossentry>

    <glossentry>
      <glossterm>swift All in One (SAIO)</glossterm>
      <indexterm class="singular">
          <primary>swift All in One (SAIO)</primary>
        </indexterm>

      <glossdef>
        <para>Creates a full Object Storage development environment within a
        single VM.</para>
      </glossdef>
    </glossentry>

    <glossentry>
      <glossterm>swift middleware</glossterm>
      <indexterm class="singular">
          <primary>swift</primary>

          <secondary>swift middleware</secondary>
        </indexterm>

      <glossdef>
        <para>Collective term for Object Storage components that provide
        additional functionality.</para>
      </glossdef>
    </glossentry>

    <glossentry>
      <glossterm>swift proxy server</glossterm>
      <indexterm class="singular">
          <primary>swift</primary>

          <secondary>swift proxy server</secondary>
        </indexterm>

      <glossdef>
        <para>Acts as the gatekeeper to Object Storage and is responsible for
        authenticating the user.</para>
      </glossdef>
    </glossentry>

    <glossentry>
      <glossterm>swift storage node</glossterm>
      <indexterm class="singular">
          <primary>storage</primary>

          <secondary>swift storage nodes</secondary>
        </indexterm>
      <indexterm class="singular">
          <primary>nodes</primary>

          <secondary>swift storage nodes</secondary>
        </indexterm>
      <indexterm class="singular">
          <primary>swift</primary>

          <secondary>swift storage nodes</secondary>
        </indexterm>

      <glossdef>
        <para>A node that runs Object Storage account, container, and object
        services.</para>
      </glossdef>
    </glossentry>

    <glossentry>
      <glossterm>sync point</glossterm>
      <indexterm class="singular">
          <primary>sync point</primary>
        </indexterm>

      <glossdef>
        <para>Point in time since the last container and accounts database
        sync among nodes within Object Storage.</para>
      </glossdef>
    </glossentry>

    <glossentry>
      <glossterm>sysadmin</glossterm>
      <indexterm class="singular">
          <primary>sysadmin</primary>
        </indexterm>

      <glossdef>
        <para>One of the default roles in the Compute RBAC system. Enables a
        user to add other users to a project, interact with VM images that are
        associated with the project, and start and stop VM instances.</para>
      </glossdef>
    </glossentry>

    <glossentry>
      <glossterm>system usage</glossterm>
      <indexterm class="singular">
          <primary>system usage</primary>
        </indexterm>

      <glossdef>
        <para>A Compute component that, along with the notification system,
        collects metrics and usage information. This information can be used
        for billing.</para>
      </glossdef>
    </glossentry>
  </glossdiv>

  <!-- .T. -->

  <glossdiv>
    <title>T</title>

    <glossentry>
      <glossterm>Telemetry</glossterm>
      <indexterm class="singular">
          <primary>Telemetry</primary>
        </indexterm>

      <glossdef>
        <para>An integrated project that provides metering and measuring
        facilities for OpenStack. The project name of Telemetry is
        ceilometer.</para>
      </glossdef>
    </glossentry>

    <glossentry>
      <glossterm>TempAuth</glossterm>
      <indexterm class="singular">
          <primary>TempAuth</primary>
        </indexterm>

      <glossdef>
        <para>An authentication facility within Object Storage that enables
        Object Storage itself to perform authentication and authorization.
        Frequently used in testing and development.</para>
      </glossdef>
    </glossentry>

    <glossentry>
      <glossterm>Tempest</glossterm>
      <indexterm class="singular">
          <primary>Tempest</primary>
        </indexterm>

      <glossdef>
        <para>Automated software test suite designed to run against the trunk
        of the OpenStack core project.</para>
      </glossdef>
    </glossentry>

    <glossentry>
      <glossterm>TempURL</glossterm>
      <indexterm class="singular">
          <primary>TempURL</primary>
        </indexterm>

      <glossdef>
        <para>An Object Storage middleware component that enables creation of
        URLs for temporary object access.</para>
      </glossdef>
    </glossentry>

    <glossentry>
      <glossterm>tenant</glossterm>

      <glossdef>
        <para>A group of users; used to isolate access to Compute resources.
        An alternative term for a project.</para>
      </glossdef>
    </glossentry>

    <glossentry>
      <glossterm>Tenant API</glossterm>
      <indexterm class="singular">
          <primary>tenant</primary>

          <secondary>Tenant API</secondary>
        </indexterm>

      <glossdef>
        <para>An API that is accessible to tenants.</para>
      </glossdef>
    </glossentry>

    <glossentry>
      <glossterm>tenant endpoint</glossterm>
      <indexterm class="singular">
          <primary>endpoints</primary>

          <secondary>tenant endpoint</secondary>
        </indexterm>
      <indexterm class="singular">
          <primary>tenant</primary>

          <secondary>tenant endpoint</secondary>
        </indexterm>

      <glossdef>
        <para>An Identity Service API endpoint that is associated with one or
        more tenants.</para>
      </glossdef>
    </glossentry>

    <glossentry>
      <glossterm>tenant ID</glossterm>
      <indexterm class="singular">
          <primary>tenant</primary>

          <secondary>tenant ID</secondary>
        </indexterm>

      <glossdef>
        <para>Unique ID assigned to each tenant within the Identity Service.
        The project IDs map to the tenant IDs.</para>
      </glossdef>
    </glossentry>

    <glossentry>
      <glossterm>token</glossterm>
      <indexterm class="singular">
          <primary>tokens</primary>
        </indexterm>

      <glossdef>
        <para>An alpha-numeric string of text used to access OpenStack APIs
        and resources.</para>
      </glossdef>
    </glossentry>

    <glossentry>
      <glossterm>token services</glossterm>
      <indexterm class="singular">
          <primary>token services</primary>
        </indexterm>

      <glossdef>
        <para>An Identity Service component that manages and validates tokens
        after a user or tenant has been authenticated.</para>
      </glossdef>
    </glossentry>

    <glossentry>
      <glossterm>tombstone</glossterm>
      <indexterm class="singular">
            <primary>tombstone</primary>
          </indexterm>
      <glossdef>
        <para>
        Used to mark Object Storage objects that have been
        deleted; ensures that the object is not updated on another node after
        it has been deleted.</para>
      </glossdef>
    </glossentry>

    <glossentry>
      <glossterm>topic publisher</glossterm>
      <indexterm class="singular">
          <primary>topic publisher</primary>
        </indexterm>

      <glossdef>
        <para>A process that is created when a RPC call is executed; used to
        push the message to the topic exchange.</para>
      </glossdef>
    </glossentry>

    <glossentry>
      <glossterm>Torpedo</glossterm>
      <indexterm class="singular">
          <primary>Torpedo</primary>
        </indexterm>

      <glossdef>
        <para>Community project used to run automated tests against the
        OpenStack API.</para>
      </glossdef>
    </glossentry>

    <glossentry>
      <glossterm>transaction ID</glossterm>
      <indexterm class="singular">
          <primary>transaction IDs</primary>
        </indexterm>

      <glossdef>
        <para>Unique ID assigned to each Object Storage request; used for
        debugging and <phrase role="keep-together">tracing</phrase>.</para>
      </glossdef>
    </glossentry>

    <glossentry>
      <glossterm>transient</glossterm>
      <indexterm class="singular">
          <primary>transient exchanges</primary>

          <see>non-durable exchanges</see>
        </indexterm>

      <glossdef>
        <para>Alternative term for non-durable.</para>
      </glossdef>
    </glossentry>

    <glossentry>
      <glossterm>transient exchange</glossterm>

      <glossdef>
        <para>Alternative term for a non-durable <phrase
        role="keep-together">exchange</phrase>.</para>
      </glossdef>
    </glossentry>

    <glossentry>
      <glossterm>transient message</glossterm>
      <indexterm class="singular">
          <primary>messages</primary>

          <secondary>transient messages</secondary>
        </indexterm>
      <indexterm class="singular">
          <primary>transient messages</primary>
        </indexterm>

      <glossdef>
        <para>A message that is stored in memory and is lost after the server
        is restarted.</para>
      </glossdef>
    </glossentry>

    <glossentry>
      <glossterm>transient queue</glossterm>
      <indexterm class="singular">
          <primary>queues</primary>

          <secondary>transient queues</secondary>
        </indexterm>
      <indexterm class="singular">
          <primary>transient queues</primary>
        </indexterm>

      <glossdef>
        <para>Alternative term for a non-durable queue.</para>
      </glossdef>
    </glossentry>

    <glossentry>
      <glossterm>TripleO</glossterm>
      <indexterm class="singular">
        <primary>TripleO</primary>
      </indexterm>

      <glossdef>
        <para>
          OpenStack-on-OpenStack program. The code name for the
          OpenStack Deployment program.
        </para>
      </glossdef>
    </glossentry>

    <glossentry>
      <glossterm>trove</glossterm>
      <indexterm class="singular">
          <primary>trove</primary>
        </indexterm>

      <glossdef>
        <para>OpenStack project that provides database services to
        applications.</para>
      </glossdef>
    </glossentry>
  </glossdiv>

  <!-- .U. -->

  <glossdiv>
    <title>U</title>

    <glossentry>
      <glossterm>Ubuntu</glossterm>
      <indexterm class="singular">
          <primary>Ubuntu</primary>
        </indexterm>

      <glossdef>
        <para>A Debian-based Linux distribution.</para>
      </glossdef>
    </glossentry>

    <glossentry>
      <glossterm>unscoped token</glossterm>
      <indexterm class="singular">
          <primary>unscoped token</primary>
        </indexterm>

      <glossdef>
        <para>Alternative term for an Identity Service default token.</para>
      </glossdef>
    </glossentry>

    <glossentry>
      <glossterm>updater</glossterm>
      <indexterm class="singular">
          <primary>updaters</primary>
        </indexterm>

      <glossdef>
        <para>Collective term for a group of Object Storage components that
        processes queued and failed updates for containers and objects.</para>
      </glossdef>
    </glossentry>

    <glossentry>
      <glossterm>user</glossterm>
      <indexterm class="singular">
          <primary>users, definition of</primary>
        </indexterm>

      <glossdef>
        <para>In Identity Service, each user is associated with one or more
        tenants, and in Compute can be associated with roles, projects, or
        both.</para>
      </glossdef>
    </glossentry>

    <glossentry>
      <glossterm>user data</glossterm>
      <indexterm class="singular">
          <primary>user data</primary>
        </indexterm>

      <glossdef>
        <para>A blob of data that the user can specify when they launch
          an instance. The instance can access this data through the
        metadata service or config drive.
      <indexterm class="singular">
            <primary>config drive</primary>
          </indexterm> Commonly used to pass a shell script that the instance runs on boot.</para>
      </glossdef>
    </glossentry>

    <glossentry>
      <glossterm>User Mode Linux (UML)</glossterm>
      <indexterm class="singular">
          <primary>User Mode Linux (UML)</primary>
        </indexterm>

      <glossdef>
        <para>An OpenStack-supported hypervisor.</para>
      </glossdef>
    </glossentry>
  </glossdiv>

  <!-- .V. -->

  <glossdiv>
    <title>V</title>

    <glossentry>
      <glossterm>VIF UUID</glossterm>
      <indexterm class="singular">
          <primary>VIF UUID</primary>
        </indexterm>

      <glossdef>
        <para>Unique ID assigned to each Networking VIF.</para>
      </glossdef>
    </glossentry>

    <glossentry>
      <glossterm>VIP</glossterm>
      <indexterm class="singular">
          <primary>VIP</primary>
        </indexterm>

      <glossdef>
        <para>The primary load balancing configuration object.
        Specifies the virtual IP address and port where client traffic
        is received. Also defines other details such as the load
        balancing method to be used, protocol, and so on. This entity
        is sometimes known in load-balancing products as a virtual
        server, vserver, or listener.</para>
      </glossdef>
    </glossentry>

    <glossentry>
      <glossterm>Virtual Central Processing Unit (vCPU)</glossterm>
      <indexterm
          class="singular">
          <primary>Virtual Central Processing Unit (vCPU)</primary>
        </indexterm>

      <glossdef>
        <para>Subdivides physical CPUs. Instances can then use those
        divisions.</para>
      </glossdef>
    </glossentry>

    <glossentry>
      <glossterm>Virtual Disk Image (VDI)</glossterm>
      <indexterm class="singular">
          <primary>Virtual Disk Image (VDI)</primary>
        </indexterm>

      <glossdef>
        <para>One of the VM image disk formats supported by Image
        Service.</para>
      </glossdef>
    </glossentry>

    <glossentry>
      <glossterm>Virtual Hard Disk (VHD)</glossterm>
      <indexterm class="singular">
          <primary>Virtual Hard Disk (VHD)</primary>
        </indexterm>

      <glossdef>
        <para>One of the VM image disk formats supported by Image
        Service.</para>
      </glossdef>
    </glossentry>

    <glossentry>
      <glossterm>virtual IP</glossterm>
      <indexterm class="singular">
          <primary>virtual IP</primary>
        </indexterm>

      <glossdef>
        <para>An Internet Protocol (IP) address configured on the load
        balancer for use by clients connecting to a service that is load
        balanced. Incoming connections are distributed to back-end nodes based
        on the configuration of the load balancer.</para>
      </glossdef>
    </glossentry>

    <glossentry>
      <glossterm>virtual machine (VM)</glossterm>
      <indexterm class="singular">
          <primary>virtual machine (VM)</primary>
        </indexterm>

      <glossdef>
        <para>An operating system instance that runs on top of a hypervisor.
        Multiple VMs can run at the same time on the same physical
        host.</para>
      </glossdef>
    </glossentry>

    <glossentry>
      <glossterm>virtual network</glossterm>
      <indexterm class="singular">
          <primary>networks</primary>

          <secondary>virtual</secondary>
        </indexterm>
      <indexterm class="singular">
          <primary>virtual network</primary>
        </indexterm>

      <glossdef>
        <para>An L2 network segment within Networking.</para>
      </glossdef>
    </glossentry>

    <glossentry>
      <glossterm>virtual networking</glossterm>
      <indexterm class="singular">
          <primary>virtual networking</primary>
        </indexterm>

      <glossdef>
        <para>A generic term for virtualization of network functions
        such as switching, routing, load balancing, and security using
        a combination of VMs and overlays on physical network
        infrastructure.
        </para>
      </glossdef>
    </glossentry>

    <glossentry>
      <glossterm>Virtual Network Computing (VNC)</glossterm>
      <indexterm class="singular">
          <primary>Virtual Network Computing (VNC)</primary>
        </indexterm>

      <glossdef>
        <para>Open source GUI and CLI tools used for remote console access to
        VMs. Supported by Compute.</para>
      </glossdef>
    </glossentry>

    <glossentry>
      <glossterm>Virtual Network InterFace (VIF)</glossterm>
      <indexterm class="singular">
          <primary>Virtual Network InterFace (VIF)</primary>
        </indexterm>

      <glossdef>
        <para>An interface that is plugged into a port in a Networking
        network. Typically a virtual network interface belonging to a
        VM.</para>
      </glossdef>
    </glossentry>

    <glossentry>
      <glossterm>virtual port</glossterm>
      <indexterm class="singular">
          <primary>ports</primary>

          <secondary>virtual</secondary>
        </indexterm>
      <indexterm class="singular">
          <primary>virtual port</primary>
        </indexterm>

      <glossdef>
        <para>Attachment point where a virtual interface connects to a virtual
        network.</para>
      </glossdef>
    </glossentry>

    <glossentry>
      <glossterm>virtual private network (VPN)</glossterm>
      <indexterm class="singular">
          <primary>virtual private network (VPN)</primary>
        </indexterm>

      <glossdef>
        <para>Provided by Compute in the form of cloudpipes, specialized
        instances that are used to create VPNs on a per-project <phrase
        role="keep-together">basis</phrase>.</para>
      </glossdef>
    </glossentry>

    <glossentry>
      <glossterm>virtual server</glossterm>
      <indexterm class="singular">
          <primary>servers</primary>

          <secondary>virtual</secondary>
        </indexterm>
      <indexterm class="singular">
          <primary>virtual servers</primary>
        </indexterm>

      <glossdef>
        <para>Alternative term for a VM or guest.</para>
      </glossdef>
    </glossentry>

    <glossentry>
      <glossterm>virtual switch (vSwitch)</glossterm>
      <indexterm class="singular">
          <primary>virtual switch (vSwitch)</primary>
        </indexterm>

      <glossdef>
        <para>Software that runs on a host or node and provides the features
        and functions of a hardware-based network switch.</para>
      </glossdef>
    </glossentry>

    <glossentry>
      <glossterm>virtual VLAN</glossterm>
      <indexterm class="singular">
          <primary>virtual VLAN</primary>
        </indexterm>

      <glossdef>
        <para>Alternative term for a virtual network.</para>
      </glossdef>
    </glossentry>

    <glossentry>
      <glossterm>VirtualBox</glossterm>
      <indexterm class="singular">
          <primary>VirtualBox</primary>
        </indexterm>

      <glossdef>
        <para>An OpenStack-supported hypervisor.</para>
      </glossdef>
    </glossentry>

    <glossentry>
      <glossterm>VLAN manager</glossterm>
      <indexterm class="singular">
          <primary>VLAN manager</primary>
        </indexterm>

      <glossdef>
        <para>A Compute component that provides dnsmasq and radvd and sets up
        forwarding to and from cloudpipe instances.</para>
      </glossdef>
    </glossentry>

    <glossentry>
      <glossterm>VLAN network</glossterm>
      <indexterm class="singular">
          <primary>networks</primary>

          <secondary>VLAN</secondary>
        </indexterm>
      <indexterm class="singular">
          <primary>VLAN network</primary>
        </indexterm>

      <glossdef>
        <para>The Network Controller provides virtual networks to enable
        compute servers to interact with each other and with the public
        network. All machines must have a public and private network
        interface. A VLAN network is a private network interface, which is
        controlled by the <literal>vlan_interface</literal> option with VLAN
        managers.</para>
      </glossdef>
    </glossentry>

    <glossentry>
      <glossterm>VM disk (VMDK)</glossterm>
      <indexterm class="singular">
          <primary>VM disk (VMDK)</primary>
        </indexterm>

      <glossdef>
        <para>One of the VM image disk formats supported by Image
        Service.</para>
      </glossdef>
    </glossentry>

    <glossentry>
      <glossterm>VM image</glossterm>
      <indexterm class="singular">
          <primary>VM image</primary>
        </indexterm>

      <glossdef>
        <para>Alternative term for an image.</para>
      </glossdef>
    </glossentry>

    <glossentry>
      <glossterm>VM Remote Control (VMRC)</glossterm>
      <indexterm class="singular">
          <primary>VM Remote Control (VMRC)</primary>
        </indexterm>

      <glossdef>
        <para>Method to access VM instance consoles using a web browser.
        Supported by Compute.</para>
      </glossdef>
    </glossentry>

    <glossentry>
      <glossterm>VMware API</glossterm>
      <indexterm class="singular">
          <primary>VMware API</primary>
        </indexterm>

      <glossdef>
        <para>Supports interaction with VMware products in Compute.</para>
      </glossdef>
    </glossentry>

    <glossentry>
      <glossterm>VMware NSX Neutron plug-in</glossterm>

      <glossdef>
        <para>Provides support for VMware NSX in Neutron.</para>
      </glossdef>
    </glossentry>

    <glossentry>
      <glossterm>VNC proxy</glossterm>
      <indexterm class="singular">
          <primary>VNC proxy</primary>
        </indexterm>

      <glossdef>
        <para>A Compute component that provides users access to the consoles
        of their VM instances through VNC or VMRC.</para>
      </glossdef>
    </glossentry>

    <glossentry>
      <glossterm>volume</glossterm>

      <glossdef>
        <para>Disk-based data storage generally represented as an iSCSI target
        with a file system that supports extended attributes; can be
        persistent or ephemeral.</para>
      </glossdef>
    </glossentry>

    <glossentry>
      <glossterm>Volume API</glossterm>
      <indexterm class="singular">
          <primary>volume</primary>

          <secondary>Volume API</secondary>
        </indexterm>

      <glossdef>
        <para>Alternative name for the Block Storage API.</para>
      </glossdef>
    </glossentry>

    <glossentry>
      <glossterm>volume controller</glossterm>
      <indexterm class="singular">
          <primary>volume</primary>

          <secondary>volume controller</secondary>
        </indexterm>

      <glossdef>
        <para>A Block Storage component that oversees and coordinates storage
        volume actions.</para>
      </glossdef>
    </glossentry>

    <glossentry>
      <glossterm>volume driver</glossterm>
      <indexterm class="singular">
          <primary>volume</primary>

          <secondary>volume driver</secondary>
        </indexterm>

      <glossdef>
        <para>Alternative term for a volume plug-in.</para>
      </glossdef>
    </glossentry>

    <glossentry>
      <glossterm>volume ID</glossterm>
      <indexterm class="singular">
          <primary>volume</primary>

          <secondary>volume ID</secondary>
        </indexterm>

      <glossdef>
        <para>Unique ID applied to each storage volume under the Block Storage
        control.</para>
      </glossdef>
    </glossentry>

    <glossentry>
      <glossterm>volume manager</glossterm>
      <indexterm class="singular">
          <primary>volume</primary>

          <secondary>volume manager</secondary>
        </indexterm>

      <glossdef>
        <para>A Block Storage component that creates, attaches, and detaches
        persistent storage volumes.</para>
      </glossdef>
    </glossentry>

    <glossentry>
      <glossterm>volume node</glossterm>
      <indexterm class="singular">
          <primary>volume</primary>

          <secondary>volume node</secondary>
        </indexterm>

      <glossdef>
        <para>A Block Storage node that runs the <systemitem
        class="service">cinder-volume</systemitem> daemon.</para>
      </glossdef>
    </glossentry>

    <glossentry>
      <glossterm>volume plug-in</glossterm>
      <indexterm class="singular">
          <primary>volume</primary>

          <secondary>volume plug-in</secondary>
        </indexterm>

      <glossdef>
        <para>Provides support for new and specialized types of back-end
        storage for the Block Storage volume manager.</para>
      </glossdef>
    </glossentry>

    <glossentry>
      <glossterm>volume worker</glossterm>
      <indexterm class="singular">
          <primary>volume workers</primary>
        </indexterm>

      <glossdef>
        <para>A cinder component that interacts with back-end storage to manage
        the creation and deletion of volumes and the creation of compute
        volumes, provided by the <systemitem
        class="service">cinder-volume</systemitem> daemon.</para>
      </glossdef>
    </glossentry>

    <glossentry>
      <glossterm>vSphere</glossterm>
      <indexterm class="singular">
          <primary>vSphere</primary>
        </indexterm>

      <glossdef>
        <para>An OpenStack-supported hypervisor.</para>
      </glossdef>
    </glossentry>
  </glossdiv>

  <!-- .W. -->

  <glossdiv>
    <title>W</title>

    <glossentry>
      <glossterm>weighting</glossterm>
      <indexterm class="singular">
          <primary>weighting</primary>
        </indexterm>

      <glossdef>
        <para>A Compute process that determines the suitability of the VM
        instances for a job for a particular host. For example, not enough RAM
        on the host, too many CPUs on the host, and so on.</para>
      </glossdef>
    </glossentry>

    <glossentry>
      <glossterm>weight</glossterm>
      <indexterm class="singular">
          <primary>weight</primary>
        </indexterm>

      <glossdef>
        <para>Used by Object Storage devices to determine which storage
        devices are suitable for the job. Devices are weighted by size.</para>
      </glossdef>
    </glossentry>

    <glossentry>
      <glossterm>weighted cost</glossterm>
      <indexterm class="singular">
          <primary>weighted cost</primary>
        </indexterm>

      <glossdef>
        <para>The sum of each cost used when deciding where to start a new VM
        instance in Compute.</para>
      </glossdef>
    </glossentry>

    <glossentry>
      <glossterm>worker</glossterm>
      <indexterm class="singular">
          <primary>workers</primary>
        </indexterm>

      <glossdef>
        <para>A daemon that listens to a queue and carries out tasks in
        response to messages. For example, the <systemitem
        class="service">cinder-volume</systemitem> worker manages volume
        creation and deletion on storage arrays.</para>
      </glossdef>
    </glossentry>
  </glossdiv>

  <!-- .X. -->

  <glossdiv>
    <title>X</title>

    <glossentry>
      <glossterm>Xen</glossterm>
      <indexterm class="singular">
          <primary>Xen</primary>
        </indexterm>

      <glossdef>
        <para>
          Xen is a hypervisor using a microkernel design, providing
          services that allow multiple computer operating systems to
          execute on the same computer hardware concurrently.
        </para>
      </glossdef>
    </glossentry>


    <glossentry>
      <glossterm>Xen API</glossterm>

      <glossdef>
        <para>The Xen administrative API, which is supported by
        Compute.</para>
      </glossdef>
    </glossentry>

    <glossentry>
      <glossterm>Xen Cloud Platform (XCP)</glossterm>
      <indexterm class="singular">
          <primary>Xen API</primary>

          <secondary>Xen Cloud Platform (XCP)</secondary>
        </indexterm>

      <glossdef>
        <para>An OpenStack-supported hypervisor.</para>
      </glossdef>
    </glossentry>

    <glossentry>
      <glossterm>Xen Storage Manager Volume Driver</glossterm>
      <indexterm class="singular">
          <primary>Xen API</primary>

          <secondary>Xen Storage Manager Volume Driver</secondary>
        </indexterm>

      <glossdef>
        <para>A Block Storage volume plug-in that enables communication with
        the Xen Storage Manager API.</para>
      </glossdef>
    </glossentry>

    <glossentry>
      <glossterm>XenServer</glossterm>
      <indexterm class="singular">
          <primary>Xen API</primary>

          <secondary>XenServer hypervisor</secondary>
        </indexterm>

      <glossdef>
        <para>An OpenStack-supported hypervisor.</para>
      </glossdef>
    </glossentry>
  </glossdiv>

  <!-- .Y. -->

  <glossdiv>
    <title>Y</title>

    <glossentry>
      <glossterm></glossterm>

      <glossdef>
        <para></para>
      </glossdef>
    </glossentry>
  </glossdiv>

  <!-- .Z. -->

  <glossdiv>
    <title>Z</title>

    <glossentry>
      <glossterm>ZeroMQ</glossterm>
      <indexterm class="singular">
          <primary>ZeroMQ</primary>
        </indexterm>

      <glossdef>
        <para>Message queue software supported by OpenStack. An alternative to
        RabbitMQ. Also spelled 0MQ.</para>
      </glossdef>
    </glossentry>

    <glossentry>
      <glossterm>Zuul</glossterm>
      <indexterm class="singular">
          <primary>Zuul</primary>
        </indexterm>

      <glossdef>
        <para>Tool used in OpenStack development to ensure correctly ordered
        testing of changes in parallel.</para>
      </glossdef>
    </glossentry>
  </glossdiv>
</glossary>