cinder-specs/specs/newton/support-backup-import-on-another-storage-database.rst

Support backup import on another Storage database

URL of launchpad blueprint:

https://blueprints.launchpad.net/cinder/+spec/support-backup-import-on-another-storage-database

• This backup service can use a backup extra metadata in order to import a backup on a different Block Storage.

Problem description

• Currently 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.
• In order to import backup metadata on another Block Storage database (i.e disaster recovery site), one has to save the metadata of a volume backup available on the source database, and then replicate it together with the data to the other Block Storage site.
• Combination of the local backup service that exports and stores this metadata, together with replication to another Block Storage site, allows you to completely restore the backup even in the event of a catastrophic database failure.
• In addition, having a backup metadata together with a volume backup, 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.

Use Cases

• When a user wants to save backup metadata together with volume backup for volume portability purpose, or for replication purpose to disaster recovery site, and be able to restore a volume from a backup on the other Block Storage site.

Proposed change

• In order to support backup import on a different Block Storage database, we need to extend chunked backup driver:
  • Enabling to save backup metadata together with the data.
  • Add a cinder client api command, that will parse backup metadata from backup_metadata file, and import that metadata to the other Block Storage database.
  • User will be able to restore a volume backup on the other Block Storage, using cinder backup restore api.

Alternatives

Support only storage on local storage. Use slow manual backup and restore methods.

Data model impact

None.

REST API impact

None.

Security impact

None.

Notifications impact

None.

Other end user impact

None.

Performance Impact

None.

Other deployer impact

None.

Developer impact

None.

Implementation

Assignee(s)

Primary assignee:

ronen-mesonzhnik

Other contributors:

None

Work Items

• Implement get_extra_metadata that will return backup's corresponding database information as encoded string metadata.
• Implement a cinder client api command that can take a backup metadata file, and do the import from it.

Dependencies

None.

Testing

None.

Documentation Impact

• In addition to the existing command 'cinder backup-import <METADATA>', there will be a command that can accept a file: 'backup-import-record-from-backup-metadata-file <file_path>'

References

• Link to Export and import backup metadata documentation: http://docs.openstack.org/admin-guide-cloud/blockstorage_volume_backups_export_import.html