Very slow tape backup after changing from Windows 2003 to 2008 R2

[SvenKessler]

Hello,

we have changed our Netbackup system from a windows 2003 server to a windows 2008 R2 system. We have used exact the same hardware with the same connections and did a fresh install. After that we imported the catalog. Everything seems to work fine, but backups to our LTO 4 tapes are 4 times slower than before. The data rate seems to reach only a quarter. I don't realy know where to search for the problem and a solution. Can you please give me a hint in the right way?

Best regards

Sven

[ROFPR]

How are the tape drives connected, SCSI or Fiber? Did you have any custom settings for buffers?

[SvenKessler]

Hello,

the tapes are connected with Fiber and i didn't find any special buffer settings in the old win 2003 system.

Best regards

Sven

[Nicolai]

Have you re-created the BPTM buffer settings  - NUMBER_DATA_BUFFERS & SIZE_DATA_BUFFERS ?

http://www.symantec.com/business/support/index?page=content&id=TECH19206

[SvenKessler]

Hello,

thank you guys for the tipps regarding the buffer size. Against my first thought i think now that it is a buffer size problem. I will test different settings on monday because now we have the old windows 2003 server running for the weekend backups. But i also tried in this system some different buffer sizes and already got some good performace boosts.

Best regards

Sven

[SvenKessler]

Hello,

it was a buffer size problem. The speed is now as good as on the win2k3 server. Still not perfect, but ok for the moment.

Best regards

Sven

[SvenKessler]

So, it's again me, but it seems that i was a little bit to quick with my last post. The speed for client based backups is ok and the speed for vSphere API VMWare Backups is also ok.

But we do have some VCB based backups which mounts our fileserver vmdk to the backup system. It's a big vmdk with almost 1.6 TB. This backup is still extremely slow. No more than maximal 10 MB/s are possible. On Windows 2003 i got 20-24 MB/s.

I've tried all the tuning parameters from this article: http://www.symantec.com/business/support/index?page=content&id=TECH19206
But no one seems to speed up vcb based backups. 

Best regards

Sven

[Nicolai]

I think you better open the question in a new thread. It will create more attention regarding the VCB issue.

Best Regards

Nicolai