Exchange GRT Backups slow, non-GRT very fast

[Seth_E]

Hi all,

I'm finding that GRT backups run at about 5 - 10 MB / sec and non-GRT runs at 44 - 50MB / sec. Same media server, same storage.

Can anyone point me in a general direction as to why this might be? Anything I can look at which can help improve performance?

We are running NB 7.6.0.3 on media server and client. - Windows 2008 R2.

[watsons]

Can we assume both the GRT & non-GRT backups are going through the same disk storage unit, and what kind of storage it is?

Any "waited for [empty|full] buffer" message found in your job details?

[Seth_E]

Correct. Same STU.

I was expecting to see "waited for empty / full buffers" but, not so in this case.

[Seth_E]

After further analysis it turns out that it was a TCP Chimmney issue. GRT backups at first were running slow, and than non-GRT started to go slow too. I than noticed socket write errors when trying to run other types of jobs with this media server. 

This technote helped:

http://www.symantec.com/docs/TECH55653

[watsons]

I see. Does it mean you have to tune the TCP Chimney value (or disable?) on the media server only? Or on both media server and client?  And your environment is probably all Windows, I suppose.