Restore a single LUN from a Snapshot copy

Contributors

You can restore a single LUN from a Snapshot copy without restoring the entire volume that contains the single LUN. You can restore the LUN in place or to a new path in the volume. The operation restores only the single LUN without impacting other files or LUNs in the volume. You can also restore files with streams.

What you’ll need
  • You must have enough space on your volume to complete the restore operation:

    • If you are restoring a space-reserved LUN where the fractional reserve is 0%, you require one times the size of the restored LUN.

    • If you are restoring a space-reserved LUN where the fractional reserve is 100%, you require two times the size of the restored LUN.

    • If you are restoring a non-space-reserved LUN, you only require the actual space used for the restored LUN.

  • A Snapshot copy of the destination LUN must have been created.

    If the restore operation fails, the destination LUN might be truncated. In such cases, you can use the Snapshot copy to prevent data loss.

  • A Snapshot copy of the source LUN must have been created.

    In rare cases, the LUN restore can fail, leaving the source LUN unusable. If this occurs, you can use the Snapshot copy to return the LUN to the state just before the restore attempt.

  • The destination LUN and source LUN must have the same OS type.

    If your destination LUN has a different OS type from your source LUN, your host can lose data access to the destination LUN after the restore operation.

Steps
  1. From the host, stop all host access to the LUN.

  2. Unmount the LUN on its host so that the host cannot access the LUN.

  3. Unmap the LUN:

    lun mapping delete -vserver vserver_name -volume volume_name -lun lun_name -igroup igroup_name

  4. Determine the Snapshot copy you want to restore your LUN to:

    volume snapshot show -vserver vserver_name -volume volume_name

  5. Create a Snapshot copy of the LUN prior to restoring the LUN:

    volume snapshot create -vserver vserver_name -volume volume_name -snapshot snapshot_name

  6. Restore the specified LUN in a volume:

    volume snapshot restore-file -vserver vserver_name -volume volume_name -snapshot snapshot_name -path lun_path

  7. Follow the steps on the screen.

  8. If necessary, bring the LUN online:

    lun modify -vserver vserver_name -path lun_path -state online

  9. If necessary, remap the LUN:

    lun mapping create -vserver vserver_name -volume volume_name -lun lun_name -igroup igroup_name

  10. From the host, remount the LUN.

  11. From the host, restart access to the LUN.