openstack-manuals/doc/common/section_cli_nova_evacuate.xml
Tom Fifield 14fc537270 Replace Havana references with Icehouse
Fix URLs to point to Icehouse, now docs.openstack.org/icehouse
is available.

Change-Id: Id614a8c7b43d707436369675d946d2a70896dd23
2014-04-18 11:00:43 +08:00

44 lines
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/icehouse/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>