openstack-manuals/doc/config-reference/block-storage/drivers/hds-hnas-driver.xml
duhzecca 4b06b3d608 HNAS documentation: Liberty Updates
- Added Manage/Unmanage section on HNAS documentation
- Few updates on HNAS storage requirements section
- Added an additional note

Change-Id: I38eb321995f8aa1e6e87768c00d3b9c0efb58dbb
2015-08-31 10:52:21 -03:00

728 lines
33 KiB
XML

<!DOCTYPE section [
<!ENTITY % openstack SYSTEM "../../../common/entities/openstack.ent">
%openstack;
]>
<section xml:id="hds-hnas-driver"
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">
<title>HDS HNAS iSCSI and NFS driver</title>
<?dbhtml stop-chunking?>
<para>This OpenStack Block Storage volume driver provides iSCSI and NFS
support for
<link xlink:href="http://www.hds.com/products/file-and-content/network-attached-storage/"
>Hitachi NAS Platform</link> Models 3080, 3090, 4040, 4060, 4080
and 4100.</para>
<section xml:id="hds-hnas-supported-operations">
<title>Supported operations</title>
<para>The NFS and iSCSI drivers support these operations:</para>
<itemizedlist>
<listitem>
<para>Create, delete, attach, and detach volumes.</para>
</listitem>
<listitem>
<para>Create, list, and delete volume snapshots.</para>
</listitem>
<listitem>
<para>Create a volume from a snapshot.</para>
</listitem>
<listitem>
<para>Copy an image to a volume.</para>
</listitem>
<listitem>
<para>Copy a volume to an image.</para>
</listitem>
<listitem>
<para>Clone a volume.</para>
</listitem>
<listitem>
<para>Extend a volume.</para>
</listitem>
<listitem>
<para>Get volume statistics.</para>
</listitem>
<listitem>
<para>Manage and unmanage a volume.</para>
</listitem>
</itemizedlist>
</section>
<section xml:id="hds-hnas-storage-reqs">
<title>HNAS storage requirements</title>
<para>
Before using iSCSI and NFS services, use the HNAS configuration and
management GUI (SMU) or SSC CLI to create storage pool(s), file system(s),
and assign an EVS. Make sure that the file system used is not
created as a <literal>replication target</literal>. Additionally:
</para>
<variablelist>
<varlistentry><term><emphasis>For NFS:</emphasis></term>
<listitem>
<para>
Create NFS exports, choose a path for them (it must
be different from "/") and set the <guilabel>Show
snapshots</guilabel> option to <literal>hide and disable
access</literal>.
</para>
<para>
Also, in the "Access Configuration" set the option <literal>norootsquash
</literal>, e.g. <option>"* (rw, norootsquash)",</option> so
HNAS cinder driver can change the permissions of its volumes.
</para>
<para>
In order to use the hardware accelerated features of
NFS HNAS, we recommend setting <literal>max-nfs-version
</literal> to 3.
Refer to HNAS command line reference to see how to
configure this option.
</para>
</listitem>
</varlistentry>
<varlistentry><term><emphasis>For iSCSI:</emphasis></term>
<listitem>
<para>You need to set an iSCSI domain.</para>
</listitem>
</varlistentry>
</variablelist>
</section>
<section xml:id="hds-hnas-cinder-reqs">
<title>Block storage host requirements</title>
<variablelist>
<varlistentry><term>The HNAS driver is supported for Red Hat, SUSE Cloud
and Ubuntu Cloud. The following packages must be installed:</term>
<listitem>
<orderedlist>
<listitem>
<para><package>nfs-utils</package> for Red Hat</para>
</listitem>
<listitem>
<para><package>nfs-client</package> for SUSE</para>
</listitem>
<listitem>
<para>
<package>nfs-common</package>, <package>libc6-i386</package>
for Ubuntu (<package>libc6-i386</package> only required on
Ubuntu 12.04)
</para>
</listitem>
<listitem>
<para>
If you are not using SSH, you need the HDS SSC package
(<package>hds-ssc-v1.0-1</package>) to
communicate with an HNAS array using the <command>SSC
</command> command. This utility package is available
in the RPM package distributed with the hardware
through physical media or it can be manually
copied from the SMU to the Block Storage host.
</para>
</listitem>
</orderedlist>
</listitem>
</varlistentry>
</variablelist>
</section>
<section xml:id="hds-hnas-pkg-install">
<title>Package installation</title>
<procedure>
<para>If you are installing the driver from a RPM or DEB package,
follow the steps bellow:</para>
<step><para>Install SSC:</para>
<para>In Red Hat:</para>
<screen><prompt>#</prompt> <userinput>rpm -i hds-ssc-v1.0-1.rpm</userinput></screen>
<para>Or in SUSE:</para>
<screen><prompt>#</prompt> <userinput>zypper hds-ssc-v1.0-1.rpm</userinput></screen>
<para>Or in Ubuntu:</para>
<screen><prompt>#</prompt> <userinput>dpkg -i hds-ssc_1.0-1_all.deb</userinput></screen>
</step>
<step><para>Install the dependencies:</para>
<para>In Red Hat:</para>
<screen><prompt>#</prompt> <userinput>yum install nfs-utils nfs-utils-lib</userinput></screen>
<para>Or in Ubuntu:</para>
<screen><prompt>#</prompt> <userinput>apt-get install nfs-common</userinput></screen>
<para>Or in SUSE:</para>
<screen><prompt>#</prompt> <userinput>zypper install nfs-client</userinput></screen>
<para>If you are using Ubuntu 12.04, you also need to install
<package>libc6-i386</package></para>
<screen><prompt>#</prompt> <userinput>apt-get install libc6-i386</userinput></screen>
</step>
<step><para>Configure the driver as described in the "Driver
Configuration" section.</para></step>
<step><para>Restart all cinder services (volume, scheduler and
backup).</para></step>
</procedure>
</section>
<section xml:id="hds-hnas-drive-config">
<title>Driver configuration</title>
<para>The HDS driver supports the concept of differentiated
services (also referred as quality of service) by mapping
volume types to services provided through HNAS.</para>
<para>HNAS supports a variety of storage options and file
system capabilities, which are selected through the definition
of volume types and the use of multiple back ends. The driver
maps up to four volume types into separated exports or file
systems, and can support any number if using multiple back
ends.</para>
<para>The configuration for the driver is read from an
XML-formatted file (one per back end), which you need to create
and set its path in the <filename>cinder.conf</filename> configuration
file. Below are the configuration needed in
the <filename>cinder.conf</filename> configuration file
<footnote xml:id="hds-hnas-no-fixed-location-1">
<para>The configuration file location may differ.</para>
</footnote>:
</para>
<programlisting language="ini">[DEFAULT]
enabled_backends = hnas_iscsi1, hnas_nfs1</programlisting>
<para>For HNAS iSCSI driver create this section:</para>
<programlisting language="ini">[hnas_iscsi1]
volume_driver = cinder.volume.drivers.hitachi.hnas_iscsi.HDSISCSIDriver
hds_hnas_iscsi_config_file = <replaceable>/path/to/config/hnas_config_file.xml</replaceable>
volume_backend_name = <replaceable>HNAS-ISCSI</replaceable></programlisting>
<para>For HNAS NFS driver create this section:</para>
<programlisting language="ini">[hnas_nfs1]
volume_driver = cinder.volume.drivers.hitachi.hnas_nfs.HDSNFSDriver
hds_hnas_nfs_config_file = <replaceable>/path/to/config/hnas_config_file.xml</replaceable>
volume_backend_name = <replaceable>HNAS-NFS</replaceable></programlisting>
<para>The XML file has the following format:
</para>
<programlisting language="xml">&lt;?xml version = "1.0" encoding = "UTF-8" ?&gt;
&lt;config&gt;
&lt;mgmt_ip0&gt;172.24.44.15&lt;/mgmt_ip0&gt;
&lt;hnas_cmd&gt;ssc&lt;/hnas_cmd&gt;
&lt;chap_enabled&gt;False&lt;/chap_enabled&gt;
&lt;ssh_enabled&gt;False&lt;/ssh_enabled&gt;
&lt;cluster_admin_ip0&gt;10.1.1.1&lt;/cluster_admin_ip0&gt;
&lt;username&gt;supervisor&lt;/username&gt;
&lt;password&gt;supervisor&lt;/password&gt;
&lt;svc_0&gt;
&lt;volume_type&gt;default&lt;/volume_type&gt;
&lt;iscsi_ip&gt;172.24.44.20&lt;/iscsi_ip&gt;
&lt;hdp&gt;fs01-husvm&lt;/hdp&gt;
&lt;/svc_0&gt;
&lt;svc_1&gt;
&lt;volume_type&gt;platinun&lt;/volume_type&gt;
&lt;iscsi_ip&gt;172.24.44.20&lt;/iscsi_ip&gt;
&lt;hdp&gt;fs01-platinun&lt;/hdp&gt;
&lt;/svc_1&gt;
&lt;/config&gt;</programlisting>
</section>
<section xml:id="hds-hnas-xml-config-options">
<title>HNAS volume driver XML configuration options</title>
<para>An OpenStack Block Storage node using HNAS drivers can have up to
four services. Each service is defined by a <literal>svc_n
</literal> tag (<literal>svc_0</literal>, <literal>svc_1</literal>,
<literal>svc_2</literal>, or <literal>svc_3</literal>
<footnote xml:id="hds-hnas-stats-all-hdp">
<para>There is no relative precedence or weight among these
four labels.</para>
</footnote>, for example). These are the configuration options
available for each service label:
</para>
<table rules="all">
<caption>Configuration options for service labels</caption>
<col width="25%"/>
<col width="10%"/>
<col width="15%"/>
<col width="50%"/>
<thead>
<tr>
<td>Option</td>
<td>Type</td>
<td>Default</td>
<td>Description</td>
</tr>
</thead>
<tbody>
<tr>
<td>
<para><option>volume_type</option></para>
</td>
<td><para>Required</para></td>
<td><para><literal>default</literal></para></td>
<td>
<para>
When a <literal>create_volume</literal> call with
a certain volume type happens, the volume type will
try to be matched up with this tag. In each
configuration file you must define the <literal>
default</literal> volume type in the service
labels and, if no volume type is specified, the
<literal>default</literal> is used. Other labels
are case sensitive and should match exactly. If no
configured volume types match the incoming
requested type, an error occurs in the volume
creation.
</para>
</td>
</tr>
<tr>
<td>
<para><option>iscsi_ip</option></para>
</td>
<td><para>Required only for iSCSI</para></td>
<td><para/></td>
<td>
<para>
An iSCSI IP address dedicated to the service.
</para>
</td>
</tr>
<tr>
<td>
<para><option>hdp</option></para>
</td>
<td><para>Required</para></td>
<td><para/></td>
<td>
<para>
For iSCSI driver: virtual file system label
associated with the service.
</para>
<para>
For NFS driver: path to the volume
(&lt;ip_address&gt;:/&lt;path&gt;) associated with
the service.
</para>
<para>
Additionally, this entry must be added in the file
used to list available NFS shares. This file is
located, by default, in
<filename>/etc/cinder/nfs_shares</filename> or you
can specify the location in the
<literal>nfs_shares_config</literal> option in the
<filename>cinder.conf</filename> configuration file.
</para>
</td>
</tr>
</tbody>
</table>
<para>
These are the configuration options available to the
<literal>config</literal> section of the XML config file:
</para>
<table rules="all">
<caption>Configuration options</caption>
<col width="25%"/>
<col width="10%"/>
<col width="15%"/>
<col width="50%"/>
<thead>
<tr>
<td>Option</td>
<td>Type</td>
<td>Default</td>
<td>Description</td>
</tr>
</thead>
<tbody>
<tr>
<td><para><option>mgmt_ip0</option></para>
</td>
<td><para>Required</para></td>
<td><para/></td>
<td>
<para>
Management Port 0 IP address. Should be the IP
address of the "Admin" EVS.
</para>
</td>
</tr>
<tr>
<td><para><option>hnas_cmd</option></para>
</td>
<td><para>Optional</para></td>
<td><para>ssc</para></td>
<td>
<para>
Command to communicate to HNAS array.
</para>
</td>
</tr>
<tr>
<td><para><option>chap_enabled</option></para>
</td>
<td><para>Optional (iSCSI only)</para></td>
<td><para><literal>True</literal></para></td>
<td>
<para>
Boolean tag used to enable CHAP authentication
protocol.
</para>
</td>
</tr>
<tr>
<td><para><option>username</option></para>
</td>
<td><para>Required</para></td>
<td><para>supervisor</para></td>
<td>
<para>It's always required on HNAS.</para>
</td>
</tr>
<tr>
<td><para><option>password</option></para>
</td>
<td><para>Required</para></td>
<td><para>supervisor</para></td>
<td>
<para>Password is always required on HNAS.</para>
</td>
</tr>
<tr>
<td>
<para>
<option>svc_0, svc_1, svc_2, svc_3</option>
</para>
</td>
<td>
<para>Optional</para>
</td>
<td>
<para>
(at least one label has to be defined)
</para>
</td>
<td>
<para>
Service labels: these four predefined
names help four different sets of
configuration options. Each can specify
HDP and a unique volume type.
</para>
</td>
</tr>
<tr>
<td>
<para>
<option>cluster_admin_ip0</option>
</para>
</td>
<td>
<para>Optional if <option>ssh_enabled</option>
is <literal>True</literal></para>
</td>
<td>
</td>
<td>
<para>
The address of HNAS cluster admin.
</para>
</td>
</tr>
<tr>
<td>
<para>
<option>ssh_enabled</option>
</para>
</td>
<td>
<para>Optional</para>
</td>
<td>
<para><literal>False</literal></para>
</td>
<td>
<para>
Enables SSH authentication between Block Storage
host and the SMU.
</para>
</td>
</tr>
<tr>
<td>
<para>
<option>ssh_private_key</option>
</para>
</td>
<td>
<para>Required if <literal>ssh_enabled</literal> is
<literal>True</literal></para>
</td>
<td>
<para><literal>False</literal></para>
</td>
<td>
<para>
Path to the SSH private key used to authenticate
in HNAS SMU. The public key must be uploaded to
HNAS SMU using <literal>ssh-register-public-key
</literal> (this is an SSH subcommand). Note that
copying the public key HNAS using
<literal>ssh-copy-id</literal> doesn't work
properly as the SMU periodically wipe out those
keys.
</para>
</td>
</tr>
</tbody>
</table>
</section>
<section xml:id="hds-hnas-service-labels">
<title>Service labels</title>
<para>
HNAS driver supports differentiated types of service using the service
labels. It is possible to create up to four types of them, as gold,
platinun, silver and ssd, for example.
</para>
<para>
After creating the services in the XML configuration file, you
must configure one <literal>volume_type</literal> per service.
Each <literal>volume_type</literal> must have the metadata <literal>
service_label</literal> with the same name configured in the
<literal>&lt;volume_type&gt;</literal> section of that
service. If this is not set, OpenStack Block Storage will
schedule the volume creation to the pool with largest available
free space or other criteria configured in volume filters.
</para>
<screen>
<prompt>$</prompt> <userinput>cinder type-create 'default'</userinput>
<prompt>$</prompt> <userinput>cinder type-key 'default' set service_label = 'default'</userinput>
<prompt>$</prompt> <userinput>cinder type-create 'platinun-tier'</userinput>
<prompt>$</prompt> <userinput>cinder type-key 'platinun' set service_label = 'platinun'</userinput>
</screen>
</section>
<section xml:id="hds-hnas-multibend-config">
<title>Multi-back-end configuration</title>
<para>
If you use multiple back ends and intend to enable the creation of
a volume in a specific back end, you must configure volume types to
set the <literal>volume_backend_name</literal> option to the
appropriate back end. Then, create <literal>volume_type</literal>
configurations with the same <literal>volume_backend_name
</literal>.
</para>
<screen><prompt>$</prompt> <userinput>cinder type-create 'iscsi'</userinput>
<prompt>$</prompt> <userinput>cinder type-key 'iscsi' set volume_backend_name = 'HNAS-ISCSI'</userinput>
<prompt>$</prompt> <userinput>cinder type-create 'nfs'</userinput>
<prompt>$</prompt> <userinput>cinder type-key 'nfs' set volume_backend_name = 'HNAS-NFS'</userinput></screen>
<para>
You can deploy multiple OpenStack HNAS drivers instances that each
control a separate HNAS array. Each service (<literal>svc_0, svc_1,
svc_2, svc_3</literal>) on the instances need to have a volume_type
and service_label metadata associated with it. If no metadata is
associated with a pool, OpenStack Block Storage filtering algorithm
selects the pool with the largest available free space.
</para>
</section>
<section xml:id="hds-hnas-ssh-config">
<title>SSH configuration</title>
<para>
Instead of using <command>SSC</command> on the Block Storage host
and store its credential on the XML configuration file, HNAS driver
supports <command>SSH</command> authentication. To configure that:
</para>
<procedure>
<step>
<para>
If you don't have a pair of public keys already generated,
create it in the Block Storage host (leave the pass-phrase
empty):
</para>
<screen><prompt>$</prompt> <userinput>mkdir -p <replaceable>/opt/hds/ssh</replaceable></userinput>
<prompt>$</prompt> <userinput>ssh-keygen -f <replaceable>/opt/hds/ssh/hnaskey</replaceable></userinput></screen>
</step>
<step>
<para>
Change the owner of the key to <literal>cinder</literal>
(or the user the volume service will be run):
</para>
<screen><prompt>#</prompt> <userinput>chown -R cinder.cinder <replaceable>/opt/hds/ssh</replaceable></userinput></screen>
</step>
<step>
<para>
Create the directory "ssh_keys" in the SMU server:
</para>
<screen><prompt>$</prompt> <userinput>ssh [manager|supervisor]@&lt;smu-ip&gt; 'mkdir -p /var/opt/mercury-main/home/[manager|supervisor]/ssh_keys/'</userinput></screen>
</step>
<step>
<para>
Copy the public key to the "ssh_keys" directory:
</para>
<screen><prompt>$</prompt> <userinput>scp<replaceable> /opt/hds/ssh/hnaskey.pub </replaceable>[manager|supervisor]@&lt;smu-ip&gt;:/var/opt/mercury-main/home/[manager|supervisor]/ssh_keys/</userinput></screen>
</step>
<step>
<para>
Access the SMU server:
</para>
<screen><prompt>$</prompt> <userinput>ssh [manager|supervisor]@&lt;smu-ip&gt;</userinput></screen>
</step>
<step>
<para>
Run the command to register the SSH keys:
</para>
<screen><prompt>$</prompt> <userinput>ssh-register-public-key -u [manager|supervisor] -f ssh_keys/hnaskey.pub</userinput></screen>
</step>
<step>
<para>
Check the communication with HNAS in the Block Storage host:
</para>
<screen><prompt>$</prompt> <userinput>ssh -i<replaceable> /opt/hds/ssh/hnaskey</replaceable> [manager|supervisor]@&lt;smu-ip&gt; 'ssc &lt;cluster_admin_ip0&gt; df -a'</userinput></screen>
</step>
</procedure>
<para>
<literal>&lt;cluster_admin_ip0&gt;</literal> is "localhost" for
single node deployments. This should return a list of available
file systems on HNAS.
</para>
</section>
<section xml:id="hds-hnas-xml-config">
<title>Editing the XML config file:</title>
<orderedlist>
<listitem>
<para>
Set the "username".
</para>
</listitem>
<listitem>
<para>
Enable SSH adding the line <literal>"&lt;ssh_enabled&gt;
True&lt;/ssh_enabled&gt;"</literal> under <literal>
"&lt;config&gt;"</literal> section.
</para>
</listitem>
<listitem>
<para>
Set the private key path: <literal>"&lt;ssh_private_key&gt;
/opt/hds/ssh/hnaskey&lt;/ssh_private_key&gt;" </literal>under
<literal>"&lt;config&gt;"</literal> section.
</para>
</listitem>
<listitem>
<para>
If the HNAS is in a multi-cluster configuration set <literal>
"&lt;cluster_admin_ip0&gt;"</literal> to the cluster
node admin IP. In a single node HNAS, leave it empty.
</para>
</listitem>
<listitem>
<para>
Restart cinder services.
</para>
</listitem>
</orderedlist>
<warning><para>Note that copying the public key HNAS using ssh-copy-id doesn't work properly as the SMU periodically wipe out those keys.</para></warning>
</section>
<section xml:id="hds-hnas-manage-unmanage">
<title>Manage and unmanage</title>
<para>
The manage and unmanage are two new API extensions that add some new features to the driver. The manage action on an existing volume is very similar to a volume creation. It creates a volume entry on OpenStack Block Storage DB, but instead of creating a new volume in the back end, it only adds a 'link' to an existing volume. Volume name, description, volume_type, metadata and availability_zone are supported as in a normal volume creation.
</para>
<para>
The unmanage action on an existing volume removes the volume from OpenStack Block Storage DB, but keeps the actual volume in the back-end. From an OpenStack Block Storage perspective the volume would be deleted, but it would still exist for use outside of it.
</para>
<note>
<title>How to Manage:</title>
<para>On Dashboard:</para>
<para>For NFS:</para>
<orderedlist>
<listitem>
<para>Under the tab System -> Volumes choose the option <guibutton>[ + Manage Volume ]</guibutton></para>
</listitem>
<listitem>
<para>
Fill the fields Identifier, Host and Volume Type with volume information to be managed:
<itemizedlist>
<listitem><para>
<guibutton>Identifier:</guibutton> ip:/type/volume_name Example: 172.24.44.34:/silver/volume-test
</para></listitem>
<listitem><para>
<guibutton>Host:</guibutton> host@backend-name#pool_name Example: ubuntu@hnas-nfs#test_silver
</para></listitem>
<listitem><para>
<guibutton>Volume Name:</guibutton> volume_name Example: volume-test
</para></listitem>
<listitem><para>
<guibutton>Volume Type:</guibutton> choose a type of volume Example: silver
</para></listitem>
</itemizedlist>
</para>
</listitem>
</orderedlist>
<para>For iSCSI:</para>
<orderedlist>
<listitem>
<para>Under the tab System -> Volumes choose the option <guibutton>[ + Manage Volume ]</guibutton></para>
</listitem>
<listitem>
<para>
Fill the fields Identifier, Host, Volume Name and Volume Type with volume information to be managed:
<itemizedlist>
<listitem><para>
<guibutton>Identifier:</guibutton> filesystem-name/volume-name Example: filesystem-test/volume-test
</para></listitem>
<listitem><para>
<guibutton>Host:</guibutton> host@backend-name#pool_name Example: ubuntu@hnas-iscsi#test_silver
</para></listitem>
<listitem><para>
<guibutton>Volume Name:</guibutton> volume_name Example: volume-test
</para></listitem>
<listitem><para>
<guibutton>Volume Type:</guibutton> choose a type of volume Example: silver
</para></listitem>
</itemizedlist>
</para>
</listitem>
</orderedlist>
<para>By CLI:</para>
<screen><prompt>$</prompt> <userinput>cinder --os-volume-api-version 2 manage [--id-type &lt;id-type&gt;] [--name &lt;name&gt;][--description &lt;description&gt;][--volume-type &lt;volume-type&gt;][--availability-zone &lt;availability-zone&gt;][--metadata [&lt;key=value&gt; [&lt;key=value&gt; ...]]] [--bootable]&lt;host&gt; &lt;identifier&gt;</userinput></screen>
<para>Example:</para>
<para>For NFS:</para>
<screen><prompt>$</prompt> <userinput>cinder --os-volume-api-version 2 manage --name &lt;volume-test&gt; --volume-type &lt;silver&gt; &lt;ubuntu@hnas-nfs#test_silver&gt; &lt;172.24.44.34:/silver/volume-test&gt;</userinput></screen>
<para>For iSCSI:</para>
<screen><prompt>$</prompt> <userinput>cinder --os-volume-api-version 2 manage --name &lt;volume-test&gt; --volume-type &lt;silver&gt; &lt;ubuntu@hnas-iscsi#test_silver&gt; &lt;filesystem-test/volume-test&gt;</userinput></screen>
</note>
<note>
<title>How to Unmanage:</title>
<para>On Dashboard:</para>
<orderedlist>
<listitem>
<para>Under the tab [ System -> Volumes ] choose a volume</para>
</listitem>
<listitem>
<para>On the volume options, choose <guibutton>[ +Unmanage Volume ]</guibutton></para>
</listitem>
<listitem>
<para>Check the data and Confirm.</para>
</listitem>
</orderedlist>
<para>By CLI:</para>
<screen><prompt>$</prompt> <userinput>cinder --os-volume-api-version 2 unmanage &lt;volume&gt;</userinput></screen>
<para>Example:</para>
<screen><prompt>$</prompt> <userinput>cinder --os-volume-api-version 2 unmanage &lt;voltest&gt;</userinput></screen>
</note>
</section>
<section xml:id="hds-hnas-additional-notes">
<title>Additional notes</title>
<itemizedlist>
<listitem>
<para>
The <literal>get_volume_stats()</literal> function always
provides the available capacity based on the
combined sum of all the HDPs that are used in these
services labels.
</para>
</listitem>
<listitem>
<para>
After changing the configuration on the storage,
the OpenStack Block Storage driver must be
restarted.
</para>
</listitem>
<listitem>
<para>
On Red Hat, if the system is configured to use SELinux, you
need to set <option>"virt_use_nfs = on"</option> for NFS
driver work properly.
</para>
</listitem>
<listitem>
<para>
It is not possible to manage a volume if there is a slash
('/') on the volume name.
</para>
</listitem>
</itemizedlist>
</section>
</section>