openstack-manuals/doc/common/section_cli_nova_evacuate.xml
Summer Long 0ccb2136b4 Moved security hardening HowTos from Config Ref to Cloud Admin
Moved procedures and theory over to the admin guide.
Also moved node recovery into its own file.
Edited trusted-flavor procedure with minor edits on rest.

Change-Id: I060d79271130d49b9c6b37638943e2f85ffae5cd
Partial-Bug: #290687
2014-04-07 20:13:59 +10:00

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2.8 KiB
XML

<?xml version="1.0" encoding="UTF-8"?>
<section 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="nova_cli_evacuate">
<title>Evacuate instances</title>
<para>If a cloud compute node fails due to a hardware malfunction or another reason, you can
evacuate instances to make them available again. You can choose evacuation parameters for
your use case.</para>
<para>To preserve user data on server disk, you must configure shared storage on the target
host. Also, you must validate that the current VM host is down; otherwise, the evacuation
fails with an error.</para>
<procedure xml:id="evacuate_shared">
<step>
<para>To list hosts and find a different host for the evacuated instance, run:</para>
<screen><prompt>$</prompt> <userinput>nova host-list</userinput></screen>
</step>
<step>
<para>Evacuate the instance. You can pass the instance password to the command by using
the <literal>--password &lt;pwd&gt;</literal> option. If you do not specify a
password, one is generated and printed after the command finishes successfully. The
following command evacuates a server without shared storage from a host that is down
to the specified <replaceable>host_b</replaceable>:</para>
<screen><prompt>$</prompt> <userinput>nova evacuate <replaceable>evacuated_server_name</replaceable> <replaceable>host_b</replaceable></userinput> </screen>
<para>The instance is booted from a new disk, but preserves its configuration including
its ID, name, uid, IP address, and so on. The command returns a password:</para>
<screen><computeroutput><?db-font-size 70%?>+-----------+--------------+
| Property | Value |
+-----------+--------------+
| adminPass | kRAJpErnT4xZ |
+-----------+--------------+</computeroutput></screen>
</step>
<step>
<para>To preserve the user disk data on the evacuated server, deploy OpenStack Compute
with a shared file system. To configure your system, see <link
xlink:href="http://docs.openstack.org/havana/config-reference/content/configuring-openstack-compute-basics.html#section_configuring-compute-migrations"
>Configure migrations</link> in <citetitle>OpenStack Configuration
Reference</citetitle>. In the following example, the password remains
unchanged:</para>
<screen><prompt>$</prompt> <userinput>nova evacuate <replaceable>evacuated_server_name</replaceable> <replaceable>host_b</replaceable> --on-shared-storage</userinput> </screen>
</step>
</procedure>
</section>