7. 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.

You can perform a rollback when the following conditions are met:

No options are available for rolling back snapshots.

7.1. Using the EVMS GUI or Ncurses

Follow these steps to roll back a snapshot with the EVMS GUI or Ncurses:

  1. Select ActionsOtherStorage Object Tasks.

  2. Select the object "snap."

  3. Click or activate Next.

  4. Select Rollback.

  5. Click or activate Next.

  6. Click or activate Rollback on the action panel.

  7. Click or activate Rollback on the warning panel.

Alternatively, you can perform these same steps with the context-sensitive menus:

  1. From the Feature Objects panel, right click (or press Enter on) the object "snap."

  2. Click or activate Rollback on the popup menu.

  3. Click or activate Rollback on the action panel.

  4. Click or activate Rollback on the warning panel.

7.2. Using the CLI

Follow these steps to roll back a snapshot with the CLI:

  1. Issue the following command to the CLI:

    task:rollback,snap
  2. Press Enter to select "Rollback" (the default choice) at the warning message.