Append yearly backup on tape not working as thought

[burak]

Hello,

Happy New Year!

As the year starts, our yearly backup was necessary.
We have a 1x Tape Job with 1x GFS media pool that backups every week on tape and once a year at the beginning of it.
However, it seems that I either misunderstand the behaviour of the yearly backup job or something in my configuration is wrong.
We had the same problem last year and as I remember correctly, I forgot to set the option "Append" to the Yearly media set.
However, this option was active before our 2025-Yearly job started this time but now some other issue happened.
The issue seems that a new media set is started and my guess would be that the wrong tape was inserted before the job started. (#1 on https://helpcenter.veeam.com/docs/backu ... ml?ver=120)
As the job started, a tape from weekly media set was still inserted which can not be used for the yearly media set. Now, a new media set starts that require an empty tape.

Can someone confirm that this is the issue and it is all by design? Therefore, if we use the wrong tape at the time of the backup we are not able to append anymore to the previously tapes?
Does someone know why this design was implemented? Would it not be much better that the job waits until a media from the correct media set is inserted and then take a look if the tape is free or from a previously media set and just append it?

If I create another GFS pool and job with yearly only, would the same issue happens again if a tape from GFS-weekly media set was inserted at start time of the yearly backup?

At some other client I just use a new tape for every year, but this one woud like to use the previously used because the tapes are 2-3x bigger than the backup size.
However, I'm open to just do the yearly backup manually since it is once a year but I'm curious about the general cause and best practice here.

Thanks!
Br
Burak

I have attached the images to my OneDrive: https://1acomputertechnik-my.sharepoint ... A?e=lxqsVK

[david.domask]

Hi Burak,

Thanks for the detailed description, and sorry to hear about the challenges.

Can someone confirm that this is the issue and it is all by design? Therefore, if we use the wrong tape at the time of the backup we are not able to append anymore to the previously tapes?

Correct, with Media Sets, there is one major rule to remember:

A new media set always begins with an empty (free) tape

I'm guessing you're correct that once the job was started and the necessary tape for Yearly wasn't inserted, a new media set was created, the previous media set was closed, and now the previous Yearly tape is protected until 2029 as per your screenshots.

Would it not be much better that the job waits until a media from the correct media set is inserted and then take a look if the tape is free or from a previously media set and just append it?

It's a balance, as in larger environments, this method would mean a lot of pausing in the tape-out process if a needed tape wasn't available. There is a wait period where the job will notify of a need for a tape and send an email notification (If configured), but in this case, it looks like an expired tape was present and used for the new media set.

Tape GFS works pretty well, and it's designed to be very "set and forget". With a smaller pool of tapes to use, there are a few finer points on the GFS logic to iron out, but it still can work pretty fine, and the options you've settled on seem reasonable for your workflow.

If I create another GFS pool and job with yearly only, would the same issue happens again if a tape from GFS-weekly media set was inserted at start time of the yearly backup?

In this case, the issue was three-fold:

1. The necessary tape was offline
2. Expired tape Woche 1 was found and marked as viable for selection (I suspect TapeGfsExpiredMediumSharing registry value may be set for this environment)
3. The expired tape was selected for starting the new media set

I think that in the future likely you will not hit this again as the conditions above lead to the situation you're in. With Append enabled and ensuring the tape is online and available for the tape drive during the yearly, this will not repeat.