low performance rates for windows servers

[felarof]

I've been playing with veeam/vcb.
i saw that i can backup linux servers about
dotCMS Success 5/6/2009 3:07:22 PM 5/6/2009 3:12:27 PM 9 9 30.00 GB 30.00 GB 101 MB/s
but for windows client with VSS or without VSS for server 2003 server 2008 or xp it's about 10MB/s or 6MB/s

is it normal ?
Best Regards

[Gostev]

Not really normal... we backup on image level, and don't really care about OS and apps inside those VMDK files. However, what does affect the speed significantly is the amount of free zeroed disk space on the VM. So if your dotCMS is nearly empty inside, that would explain why the speed is so much faster.

Also - is this statistics for incremental backup pass, or full (initial backup)? Both VMs are located on the same LUN/ESX? Processed by the same job or different jobs with the same backup destination?

[felarof]

full backup. the windows server have lots of space too. Must i enable shadow copy for vss integration backups ?

[Gostev]

No, in fact VSS integration would slow down snapshot creation for about 10 seconds comparing with no VSS. So for the sake of performance experiments, it is best not to use it.

While your windows server has lotsa free space, if it is "old" VM then most likely all currently free disk space used to host files before, and therefore does not contain zeroed blocks that Veeam Backup could drop from processing (which is what results in faster processing speed). I suggest that you give defrag+wipe a try, then try full backup again to see if it helped.

[MadDog2K]

I get 33MB/s max as backup speed, but 14 - 20 is more usual.
Don't use VCB (because I use ESXi free).

Since it's agentless, I don't think there's a lot of speed improvement possible ?
The defrag/wipe option was done, but don't differ for the speed.

[Gostev]

That is correct, there is no way to improve ESXi backup speed beyond what you are getting.