openstack/openstack-manuals
Code Issues Proposed changes

Added instructions on volume backup and export

Browse Source 
This patch adds two sections: one for volume backup, and the other for
exporting volume metadata. The feature in focus here is the volume
metadata export, which makes volume backups portable across cloud
services and also recoverable even in the event of cinder database
failure.

Partially implements: https://blueprints.launchpad.net/cinder/+spec/cinder-backup-recover-api
Partially implements: https://blueprints.launchpad.net/cinder/+spec/cinder-backup-volume-metadata-support

Change-Id: I0ffa0c7ab9b9ecd3449e93390099e8d0001c8efd
This commit is contained in:
Don Domingo 2014-04-11 11:15:16 +10:00 committed by Anne Gentle
parent fb98f857ea
commit 29d7064fe9
3 changed files with 74 additions and 0 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

2
doc/admin-guide-cloud/ch_blockstorage.xml
View File

@ -125,6 +125,8 @@
<xi:include href="section_backup-block-storage-disks.xml"/> <xi:include href="section_backup-block-storage-disks.xml"/>
<xi:include href="section_volume-migration.xml"/> <xi:include href="section_volume-migration.xml"/>
<xi:include href="section_glusterfs_removal.xml"/> <xi:include href="section_glusterfs_removal.xml"/>
<xi:include href="section_volume-backups.xml"/>
<xi:include href="section_volume-backups-export-import.xml"/>
</section> </section>
<section xml:id="troubleshooting-cinder-install"> <section xml:id="troubleshooting-cinder-install">
<title>Troubleshoot your installation</title> <title>Troubleshoot your installation</title>

41
doc/admin-guide-cloud/section_volume-backups-export-import.xml Normal file
View File

@ -0,0 +1,41 @@
<?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="volume-backup-restore-export-import">
<title>Export and import backup metadata</title>
<para>A volume backup can only be restored on the same Block
Storage service. This is because restoring a volume from a backup
requires metadata available on the database used by the Block
Storage service.</para>
<note><para>For information on how to back up and restore a
volume, see <xref linkend="volume-backup-restore"/>.</para></note>
<para>You can, however, export the metadata of a volume backup. To
do so, run this command as an OpenStack <literal>admin</literal>
user (presumably, after creating a volume backup):
</para>
<screen><prompt>$</prompt> <userinput>cinder backup-export <replaceable>backup_ID</replaceable></userinput></screen>
<para>Where <replaceable>backup_ID</replaceable> is the volume
backup's ID. This command should return the backup's corresponding
database information as encoded string metadata.</para>
<para>Exporting and storing this encoded string metadata allows
you to completely restore the backup, even in the event of a
catastrophic database failure. This will preclude the need to
back up the entire Block Storage database, particularly if you
only need to keep complete backups of a small subset of
volumes.</para>
<para>In addition, having a volume backup and its backup metadata also
provides volume portability. Specifically, backing up a volume and
exporting its metadata will allow you to restore the volume on a
completely different Block Storage database, or even on a different
cloud service. To do so, first import the backup metadata to the Block
Storage database and then restore the backup. </para>
<para>To import backup metadata, run the following command as an
OpenStack <literal>admin</literal>:</para>
<screen><prompt>$</prompt> <userinput>cinder backup-import <replaceable>metadata</replaceable></userinput></screen>
<para>Where <replaceable>metadata</replaceable> is the backup
metadata exported earlier.</para>
<para>Once you have imported the backup metadata into a Block Storage
database, restore the volume (<xref
linkend="volume-backup-restore"/>).</para>
</section>

31
doc/admin-guide-cloud/section_volume-backups.xml Normal file
View File

@ -0,0 +1,31 @@
<?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="volume-backup-restore">
<title>Back up and restore volumes</title>
<para>The <command>cinder</command> command-line interface
provides the tools for creating a volume backup. You can restore
a volume from a backup as long as the backup's associated database
information (or backup metadata) is intact in the Block Storage
database.
</para>
<para>Run this command to create a backup of a volume:</para>
<screen><prompt>$</prompt> <userinput>cinder backup-create <replaceable>VOLUME</replaceable></userinput></screen>
<para>Where <replaceable>VOLUME</replaceable> is the name or ID of
the volume.</para>
<para>The previous command will also return a backup ID. Use this
backup ID when restoring the volume, as in:</para>
<screen><prompt>$</prompt> <userinput>cinder backup-restore <replaceable>backup_ID</replaceable></userinput></screen>
<para>As mentioned earlier, volume backups are dependent on the
Block Storage database. Because of this, we recommend that you
also back up your Block Storage database regularly in order to
ensure data recovery.</para>
<note><para>Alternatively, you can export and save the metadata of
selected volume backups. Doing so will preclude the need to
back up the entire Block Storage database. This is particularly
useful if you only need a small subset of volumes to survive a
catastrophic database failure.</para>
<para>For more information on how to export and import volume
backup metadata, see <xref linkend="volume-backup-restore-export-import"/>.</para></note>
</section>