im currently looking for backup software that supports tape drives. this is not looking too good :_I

I invented a machine that converts masking tape you can buy at the dollar store into backup tapes. I rewrote Bacula to write the backup AND print pretty flowers on the masking tape. Totally free and open-source. Download it from a rotary phone.

No answer here, but I just want to point out that according to that graph, you can gain an extremely high skill level in Bacula in a very short time!
It would seem to be the easiest to learn based on this one cartoon.

(Related: the phrase "steep learning curve" means the opposite of the way it's usually used)

If you're going for WORM or similar strategy, and you just want to dump archival backups to tape, you can probably just use dd or even tar (originates frome Tape ARchive), possibly with cron.

Use AMANDA

https://www.amanda.org/

If that's bacula, what's tar?

When I did that, I used veeam to create the VM backup files to disc, then called a script to compress and encrypt the files, then called a second script to copy the encrypted files to tape. It worked really well. I used the free veeam license, so backup to tape wasn't included, but copy to tape was.

E: FinalBoy1975 seemed to have invented something that could be the solution, but they used masking tape, which I found tears easily. Now, if they'd use scotch tape, we'd be golden hahahaa

I love Bacula, so hard to setup but once it's going you'll never have to worry again

Checkout Proxmox Backup Server paired with Proxmox Backup Client.