Restore a Backup that Has No Associated VolumeSnapshot
To restore Longhorn backups that have not been created via the CSI mechanism, you have to first manually create a VolumeSnapshot and VolumeSnapshotContent object for the backup.
Create a VolumeSnapshotContent object with the snapshotHandle field set to bs://backup-volume/backup-name.
The backup-volume and backup-name values can be retrieved from the Backup page in the Longhorn UI.
# NOTE: change this to point to an existing backup on the backupstoresnapshotHandle: bs://test-vol/backup-625159fb469e492e
Create the associated VolumeSnapshot object with the name field set to test-snapshot-existing-backup, where the source field refers to a VolumeSnapshotContent object via the volumeSnapshotContentName field.
This differs from the creation of a backup, in which case the source field refers to a PerstistentVolumeClaim via the persistentVolumeClaimName field.
Only one type of reference can be set for a VolumeSnapshot object.