File backup to Tape compression

[B.F.]

Using a stand alone LTO-4 tape drive and tape. Capacity of the tapes are 800gb uncompressed and up to 1,600gb compressed (almost never happens). Created a job with compression enabled that would go over the limit of the tape to see how Veeam reacts. I was quite surprised to see that it wanted another tape just after only saving 711gb. This was the first time Veeam had used this tape so it should not had done any sort of append. I double checked the tape drive in the OS's (Server 2012 R2) device manager and compression is enabled.

Does compression work on Veeam tape backup jobs? Is there something I could have missed when running this test?

Thanks

[Dima P.]

Hi B.F.

Most probably it's related to the End Of Media (EOM) command which is returned by tape device to our software during backup process. Generally, vendors keep up to 10% of tape media free for internal purposes (check this discussion).

Does compression work on Veeam tape backup jobs? Is there something I could have missed when running this test?

Keep in mind, if you are writing VBR’s backup files to tape – compression might be enabled in the source backup jobs.

[B.F.]

Keep in mind, if you are writing VBR’s backup files to tape – compression might be enabled in the source backup jobs.

I should have probably clarified. I'm using the "File to Tape Backup" feature.

I don't have an LTO-4 drive hooked up to the production Backup Exec server but it does have an LTO-5 made by the same manufacture (Quantum). LTO-5 capacity is 1500gb / 3000gb (uncompressed / compressed). Looking at the tape backup history on BE, I can see that BE is getting around 1570gb on one tape with compression enabled. I know I should hook up the LTO-4 to do a 1:1 test between BE and Veeam but this is what I have available at the moment.

Is there any way to confirm that the data on the tape is indeed getting compressed? Even with EOM commands from the drive, one should expect to get closer if not a tad over capacity using compression like we are seeing with BE.

Thanks

[gavrun]

Hi

Speaking about a file to tape job.. Does Veeam use a native compression, or libraries/drives utilize hardware compression? Does Veeam offer a possibility to monitor a compression ratio in UI while backing up files to tapes?

Links to refer:
https://helpcenter.veeam.com/docs/backu ... tml?ver=95
https://helpcenter.veeam.com/docs/backu ... tml?ver=95

[veremin]

We do not provide any own compression mechanism for file to tape job. If you want to have compression, utilize hardware one.

[DaveWatkins]

I double checked the tape drive in the OS's (Server 2012 R2) device manager and compression is enabled.

I'm pretty sure you have to enable it in Veeam too. In the job itself under Options there is an Advanced button, in there is an option to enable hardware compression too

[veremin]

Correct, to leverage hardware compression you should enable it via device native tool and also do so in settings of file to tape job. Thanks.