Backup several jobs into one tape without erasing pervious jobs

[aabacker]

Hello Everyone,
I would like to understand something because I had a tape that was installed by my previous colleague.
So, we have a tape that is 12TB of size, and it was assigned into a monthly pool in the tape library which is used for monthly backups.
Now how the monthly backups operate into tapes is:
Layer 1: We have daily backups of VMs to local server -> Layer 2: we have weekly Archiving jobs which is a backup and compression of the first layer -> Layer 3: Monthly backup to tape which is a backup from the second layer into the tape.
The tape jobs are currently configured to the selected media pool (monthly backups), however, in the Incremental Backup tab the "Archive incremental backups to tape" is diabled, and in the next [options] tab, the "Eject tape media upon job completion" is selected.
Now what is happening here is that the monthly job that is backing up to tape is no more than 1TB in size, and our tapes are 12TB. After each of the backups, we are losing 11TB that are becoming unusable.
How can I configure the job to be able to backup several months continuously to make use of the full 12TB without deeming the tape unusable after each job?


Thank you everyone!

[Mildur]

Hi aabacker

Are you using a GFS media Pool? Do you export the monthly media set? When you have enabled "Export the following media sets upon job completion", for each run a new tape is required.

Thanks
Fabian

[aabacker]

Thank you for your answer Mildur,
No, we are not using GFS media pool, just a standard one.
I was doing some reading around, and came across one possible solution which is yet to be confirmed:
"Disabling automatic creation of media set will make use of the entire disk/tape space" this way it is supposed to continue writing the next backups on the same disk until it is full. which on the other hand, makes me wonder, what if the tape is about to be full, and there is another free one, would it start writing on the free one, or split the backup between disks? This might be a tricky situation.

There was also another thing that caught my eye, in the job settings "eject tape media upon job completion", which I also disabled for testing, since I am not entirely sure what does "eject" stands for here.


Thanks again.

[Mildur]

Hi Aabacker

There was also another thing that caught my eye, in the job settings "eject tape media upon job completion", which I also disabled for testing, since I am not entirely sure what does "eject" stands for here.

There was a misunderstanding on my side.
Exporting a tape is only relevant for tape libraries with an mail slot (Import/Export slot).
It moves the tapes from the slots in the tape device to the Import/Export slot.
Ejecting a tape means, it is moved from the tape drive to a free tape slot in a tape library.
In case you are using a standalone tape drive, ejecting a tape does the same as exporting.

Disabling automatic creation of media set will make use of the entire disk/tape space" this way it is supposed to continue writing the next backups on the same disk until it is full.

Yes, this should work.

which on the other hand, makes me wonder, what if the tape is about to be full, and there is another free one, would it start writing on the free one, or split the backup between disks? This might be a tricky situation.

Let me check. I'll update this topic after I got an answer on this question.

Thanks
Fabian

[Mildur]

If a backup file needs to be written to a Tape without enough space left, the file will be split over both tapes.

May I know your required retention for this monthly tape backups?
Because, if you never create a new media set, there is no way to delete a single monthly backup. Only entire tapes can be erased. You can't delete a single backup file from a tape.
Also, a tape should be removed from the library/standalone drive. If not, an attacker can easily delete your tape backups.

Thanks
Fabian

[aabacker]

Thank you for getting back with all the answers, the painting is forming nicely now.
The best intended practice from our side is to have one media pool per month, not the purpose of deletion or not, but to split and organize backups as much as possible. However, on the other hand, no backups would be ever deleted, once the tape is full, it is taken out to safekeeping in a different physical location.
This is the conclusion, the closer we can get towards it, the better.

Thank you.