ce4f54732f
Clarify that evacuate method is preferred over manual for node recovery Edit broken and obsolete external guide references Remove gerunds in related files Address request for stylistic edits from review Address linking issues from review Change-Id: Iccf188ad89a8cc277966cb9c0a530ba24613127b Closes-Bug:#1222735
50 lines
2.9 KiB
XML
50 lines
2.9 KiB
XML
<?xml version="1.0" encoding="UTF-8"?>
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<section xmlns="http://docbook.org/ns/docbook"
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xmlns:xi="http://www.w3.org/2001/XInclude"
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xmlns:xlink="http://www.w3.org/1999/xlink" version="5.0"
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xml:id="nova_cli_evacuate">
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<title>Evacuate instances</title>
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<para>If a cloud compute node fails due to a hardware malfunction
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or another reason, you can evacuate instances to make them
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available again.</para>
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<para>You can choose evacuation parameters for your use case.</para>
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<para>To preserve user data on server disk, you must configure
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shared storage on the target host. Also, you must validate
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that the current VM host is down. Otherwise the evacuation
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fails with an error.</para>
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<procedure xml:id="evacuate_shared">
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<title>To evacuate your server</title>
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<step>
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<para>To find a different host for the evacuated instance,
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run the following command to lists hosts:</para>
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<screen><prompt>$</prompt> <userinput>nova host-list</userinput></screen>
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</step>
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<step>
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<para>You can pass the instance password to the command by
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using the <literal>--password <pwd></literal>
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option. If you do not specify a password, one is
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generated and printed after the command finishes
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successfully. The following command evacuates a server
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without shared storage:</para>
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<screen><prompt>$</prompt> <userinput>nova evacuate <replaceable>evacuated_server_name</replaceable> <replaceable>host_b</replaceable></userinput> </screen>
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<para>The command evacuates an instance from a down host
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to a specified host. The instance is booted from a new
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disk, but preserves its configuration including its
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ID, name, uid, IP address, and so on. The command
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returns a password:</para>
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<screen><computeroutput><?db-font-size 70%?>+-----------+--------------+
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| Property | Value |
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+-----------+--------------+
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| adminPass | kRAJpErnT4xZ |
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+-----------+--------------+</computeroutput></screen>
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</step>
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<step>
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<para>To preserve the user disk data on the evacuated
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server, deploy OpenStack Compute with shared
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filesystem. To configure your system, see <link xlink:href="http://docs.openstack.org/trunk/config-reference/content/configuring-openstack-compute-basics.html#section_configuring-compute-migrations">Configure migrations</link> in <citetitle>OpenStack Configuration Reference</citetitle>. In this
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example, the password remains unchanged.</para>
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<screen><prompt>$</prompt> <userinput>nova evacuate <replaceable>evacuated_server_name</replaceable> <replaceable>host_b</replaceable> --on-shared-storage</userinput> </screen>
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</step>
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</procedure>
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</section>
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