openstack-manuals/doc/admin-guide/source/blockstorage-volume-backups-export-import.rst

Export and import backup metadata

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.

Note

For information about how to back up and restore a volume, see the section called volume_backups.

You can, however, export the metadata of a volume backup. To do so, run this command as an OpenStack admin user (presumably, after creating a volume backup):

$ cinder backup-export BACKUP_ID

Where BACKUP_ID is the volume backup's ID. This command should return the backup's corresponding database information as encoded string metadata.

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.

If you have placed encryption on your volumes, the encryption will still be in place when you restore the volume if a UUID encryption key is specified when creating volumes. Using backup metadata support, UUID keys set up for a volume (or volumes) will remain valid when you restore a backed-up volume. The restored volume will remain encrypted, and will be accessible with your credentials.

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.

To import backup metadata, run the following command as an OpenStack admin:

$ cinder backup-import METADATA

Where METADATA is the backup metadata exported earlier.

Once you have imported the backup metadata into a Block Storage database, restore the volume (see the section called volume_backups).