Backup on LTO 6 Tape only 1.5 TB

[BenJo83]

Hello, I have a Problem with a Backup to Tape Job. We bought new LTO 6 Tapes and I added them to the veeam Media Pool. But instead of storing 2,3 TB on a tape, Veeam only stores 1,5 TB on that tape. Any clue what is causing that?

Regards
BenJo83

[Mildur]

Hello Ben

Welcome to the forum.

But instead of storing 2,3 TB on a tape, Veeam only stores 1,5 TB on that tape.

I assume your full backup has only a size of 1.5 TB and the media set was closed after the tape job has written it to the tape.
If you like to confirm it, please open a case with our customer support team to check the logs of your server.

Best,
Fabian

[BenJo83]

HI Fabian,

no the Backup size is 8,8 TB. We are using a Tape Library. I checked in Veeam the properties of the first tape used (the job is still running) and veeam says there are only 3,3 GB free of 2,3 TB. But I checked the files that are stored on the tape and they only sum up to 1,45 TB. But ok then I will open a support case.

Regards BenJo83

[FabriceMagier]

Hi,

I have the same problem. LTO6 caooacity 2,3TB and my backup is 1,7TB. But Veeam use 2 tapes 1 tpae "full" and 1 tape with 3 Go !

With v12.0 i have no problem. With 12.1 it's incomprehensive.

And Support Veeam say "It's Ok". But i'm not agree!!!!
(case 07251810)

[david.domask]

Hi Fabrice,

Sorry to hear about the challenges, and thank you for sharing the case number.

Checking the case quickly, I see that the End of Media (EOM) marker was observed by the Engineer on the case; the original poster did not share a case number so I cannot comment on the result of that investigation, but the EOM marker tells software when the tape is full and indicates that the medium should be exchanged.

If the job wrote significantly less data than the tape capacity and the tape returned the EOM marker, it may be indicative of an issue with the tape or the drive itself (write failures can be retried further down on the tape, which has the end result of "filling" the tape faster than expected)

You might try a full write test with your tape hardware vendor's native utility (use uncompressible data for the test), and see if it also is writing less than the tape's capacity. If you cannot reproduce it, I'd ask you please open a new case and share the case number here for our review.