backup to tape slow write speed

[Tomas Snajdar]

Hello,

I have an issue with backups to tape.

Right now I am using Quantum Scalar i40-i80 190G (IBM Ultrium-HH7 drive) with LTO-6 tapes.

Tape drive is directly connected via fiber to LUN (so there should not be the issue) on our repository.

Write speed for jobs (jobs with 5-6 VM or jobs with 1 VM - same results) is 100MB/s.

I tested also file to tape job, where I used 500GB .vbk file. Same 100MB/s result.

.VBK files are configured on optimal compression level.

I tested backup to tape with and also without hardware compression, but still with same result 100MB/s.

I am no expert, but I think that this is not optimal write speed for this configuration and in worst case it should runs around 150MB/s +- in uncompressed mode.

Could you give me some tips or help where could by issue and where I should start to solve my issue ?

Thank you and have a nice day.

[Dima P.]

Hello and welcome to the community Tomas,

Can you please clarify what is your Veeam B&R version? Please check what is the block size value for the drive in the question (and what is the possible maximum)? Thank you!

[Tomas Snajdar]

Hello Dima,

I am using Enterprise Edition of 9.5 U4 version.

Block size for drive is configured to 262144 and max available option for size is 524288.

[Tomas Snajdar]

I missed information that Veeam shows bottleneck for all jobs as "Target", but in time when tape job was running was only this job active

[Dima P.]

Can you please clarify what type of backup repository you are using? Any chance your tape server (Veeam B&R role to manage tape device) is located on the same repository machine? Thanks!

[Tomas Snajdar]

Our repository is a Windows 2016 Hewlett Packard server Proliant DL380 Gen9. Storage is 3PAR.

The tape drive is presented to the repository via the LUN. It is actually physically attached to the Quantum tape library.

[Dima P.]

Tomas,

Kindly check that Tape Sever role is installed on the repository machine. Thanks!

[Tomas Snajdar]

He,

I double checked it and yes tape server is directly connected to our repository server. Also I tested tape job to use Repository proxy (with disabled Veeam server Proxy) and speed is still same.

Percent busy for processing stages were:

Source 6%
Proxy 1%
Network 10%
Target 99%

Do you have another suggestions where could be issue ?

[Dima P.]

Tomas,

I believe that test via native vendor tools is required to compare the results. You can open a support case and let our team help you with it. If you do, please share your case ID in this thread.

[mma]

Was this issue resolved?

We have a "simpe" installation (Mgmt, Repo, Proxy, Tape) on the same physical server.
Tape Performance in 9.5 U3 was about 190 MB/s without a real bottleneck (Load: Source 79% > Proxy 49% > Network 48% > Target 72%).
We installed 9.5 Update4b and the write performace dropped to about 50 MB/s with bottleneck ond the target side (Busy: Source 2% > Proxy 68% > Network 7% > Target 99%).

No other changes were made.

[edit]
Slow Jobs: New tape backup session started, encryption: software
Fast Jobs: New tape backup session started, encryption: hardware
[/edit]



Thanks
Marcel

[Dima P.]

Hello Marcel,

Can you please clarify if the KB 2981 was installed or not? Thank you!

[mma]

Hello Dima

I just installed https://www.veeam.com/kb2983 and it works again. Performacne and hardware encryption is back!

[Dima P.]

mma,

Glad to hear it and thank you for confirmation that your issue is now resolved. Cheers!