Mannual Tape cartridge management

We had a similar situation in the past where we'd tell the higher ups that a large tape library is needed for all the direct-to-tape backups to be kept on-site, and then they saying:
"Here, have this 1U tape autoloader with 8 slots. You're welcome."

1. NetBackup Vault should handle this nicely. License(s) is needed to enable the Vault feature.

2. Without Vault, you'd have to manually select and eject tapes. You'd also have to manually keep track of the tapes that have been taken out, and remind yourself to put the expired ones back in for reuse.

3. It is doable, more so with the help of Nbu Vault, but an easier approach would be to invest in Deduplication (MSDP/Nbu Appliance/3rd party, etc.), or, overlook the cost issue and get the larger tape library. Think of it as giving you a lower operational cost in the long run...

4. With Nbu Vault you could vault (I.e., auto-eject and track) original backup tapes, and/or duplicated copies of those tapes. You can schedule the vault job to run whenever, typically once per week or month. Tapes that contain backups will be ejected, which frees up slots for you to insert empty tapes.
These "empty tapes" you put in could also be tapes that were previously vaulted and have been out for long enough for their backups to have expired. Nbu Vault Reports will automaticlly remind you to put them back in for reuse.
This completes the tape rotation cycle.
A caveat would be the frequent tape-in tape-out operational annoyance, and along with it the potential human errors.

P.S.: We were grateful for the high-tech robotic arm and futuristic barcode scanner that came with the 8 slot tape autoloader (We called it Johnny 5). I mean, they could have bestowed us with a standalone tape drive.
Jonny 5 has been dead for a long time now.