I attempted to back up 11 TB of data to LTO6 tapes on a Dell T630 running Windows 2016 using Veritas 21.1 Rev 1200.1217. Once the first tape filled it was automatically ejected and I was prompted to insert a new blank tape. After I got to the fifth iteration the last tape ejected and I blindly inserted a sixth blank tape. However, I was actually prompted to reinsert the first tape, but it was too late and the Backup process failed. I have been unable to restore more then 1 tape on a single server. Once one tape has been inventoried and catalogued and restored, I am unable to inventory and catalog any additional tapes and only the initial backup set exists on the server. Is there a way to fix or get around this mistake? All of the data appears to be on the tapes.
Check your joblog to see what is the failure. If it is a failure of the verify process, then your backup set is probably good. You don't have to inventory and catalog the tapes again. You can just select the necessary items to restore and the restore job would prompt you to insert the right tapes in the right sequence. You might want to make the tapes read-only.
If you plan to do this big backup regularly in the future, I would suggest that you get a tape library.