About data restoration

When to restore data from tape

You restore data from tape under the following circumstances:

Files were deleted from disk but backed up to tape.
For example, if you inadvertently delete a file and want to restore the file, you can recover the file from tape.
Files are corrupted. If some files are corrupted, you can restore the subtree containing the files.
No disk slots are available for expansion. If the filer runs out of storage space, you can do the following tasks:
- Back up the entire filer.
- Replace the current disks with disks of greater capacity.
- Set up volumes on new disks.
- Restore the filer from tapes.
The entire filer is damaged and unusable. Call Network Appliance Technical Support to determine whether you can repair the filer and restore data from tape.

When not to restore data from tape

You do not need to restore a deleted file from tape if you can recover the deleted file from a snapshot on the filer. If the file is in a snapshot, copying the file to the active file system is faster than recovering the file from tape.

Note
If you attempt an incremental restore to a filer running Data ONTAP 6.2 or later from a filer running a version earlier than 6.2, the restore will fail because of a formatting code change between the two code releases. You need to run the full backup again after you have upgraded to 6.2.