File to tape backup is very slow

[adam900331]

Hello!

I have a Veeam B&R server which has a local storage and attached a tape library to this server via SAS connection. When I start a file to tape job, the speed is very slow I think. There is a 20Gb file in the local storage but the speed is:

Processing rate: 84Mb/s

I think it would be higher. Whats wrong?

Thanks.

[Egor Yakovlev]

Hi Adam,

it depends on many factors, however first of all I would check your LTO type and drive specs.
For example, LTO3 cartridge maximum write speed will be roughly 80MB\s(uncompressed).
Check your tape library vendor native Tape Diagnostics tools and measure performance using those. If write speed using native tool will be different, then we can search for possible bottleneck elsewhere - say source disk performance.

Thanks!

[adam900331]

It is a HPE LTO-6 Ultrium 6.25 TB MP RW Data Cartridge.

But I have another question. The tape capacity is 6.25 TB, but the Veeam is only see 2.4 TB. Why?

[tdewin]

Because the actually raw capacity is 2.5TB. 6.25TB you might potentially hit when the data is getting compressed by the library/drive but since Veeam Backups are already compressed by us, those gains are near 0
https://en.wikipedia.org/wiki/Linear_Tape-Open