12.6. Rolling back a snapshot

Situations can arise where a user wants to restore the original volume to the saved state of the snapshot. This action is called a rollback. One such scenario is if the data on the original is lost or corrupted. Snapshot rollback acts as a quick backup and restore mechanism, and allows the user to avoid a more lengthy restore operation from tapes or other archives.

Another situation where rollback can be particularly useful is when you are testing new software. Before you install a new software package, create a writeable snapshot of the target volume. You can then install the software to the snapshot volume, instead of to the original, and then test and verify the new software on the snapshot. If the testing is successful, you can then roll back the snapshot to the original and effectively install the software on the regular system. If there is a problem during the testing, you can simply delete the snapshot without harming the original volume.

Rollback can only be performed when both the snapshot and the original volumes are unmounted and otherwise not in use. Rollback can also be performed only when there is only a single snapshot of an original. If an original has multiple snapshots, all but the desired snapshot must be deleted before rollback can take place.

No options are available for rolling back snapshots.