The dummy restore is a method of validating that the save-type (account-save, file-save, and so on) backup are restored.
There are three methods to validate backup media:
Using the t-chk command, which looks for parity errors, but does not actually verify data.
Issuing a dummy restore, using the sel-restore command with the n option, without actually writing any items back to disk. This not only checks for parity errors, but also validates the logical format of the tape. If the media cannot be restored, another backup can be made.
Using the t-verify command, which has the ability to not only do the same as the first two methods, but also can compare each record from the media with its counterpart on disk to verify that they match. This is the most reliable way to check tape integrity.
Restore from Full, incremental, transaction log (f/i/t):f file#:99999
Reads every file in every account on the full save tape, looking for file number 99999 and in the process, reads the entire tape.
sel-restore md * (n