With Tape Media retention, the Backup Jobs on Tape will follow the same method of calculation as Backup on Disk. If there are still backup on Tape, it might be associated to another cycle or required for another purpose.
You can definitely delete the content of the Tapes (ensuring that you are 100% sure its not required), so the Media will be returned to the Tape Library as "Aged" (which is the same as scratch media). During the next Aux Copy/Backup to Tape, the "Aged" media will be selected and used.
The above is the standard mechanism of Data Aging:
- Backup jobs that meet retention will be logically submitted to the CommServe DB
- The references to the Job will be marked as aged.
- Once all the Backup Jobs on the Tape Media has met retention, the Tape will then be marked as "aged', returned to the Tape Library (if exported), and then re-use.
Note - even if there is one backup job on tape that hasn't met retention, the Tape Media will not be marked as "Aged".
It would be advisable to review the content on the Tape Media, and try to confirm from CommVault "Data Retention & Forecast" report to determine why Jobs are not aging.
Hopefully that answers your question.