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VM's backup speed rate cut in half

james_richard2
Level 4

Hello,

About 2 weeks ago, 1 of our VM's that is backed up through remote agent has been taking twice as long to backup. It's speed rate has dropped by at nearly half, It's been doing it ever since 2 weeks ago.

It's backs up after another phyiscal server job has finished first (Not the Host server). I looked into the logs in Windows event viewer but it doesn't tell me anything.

Regards,

James

11 REPLIES 11

james_richard2
Level 4

Any ideas??

Thanks,

James

Gurvinder
Moderator
Moderator
Employee Accredited Certified

can you share the Job Log for the backup which was working fine and the one which was slower ? have you changed any NIC settings on that VM which is being backed up using the remote agent. Can you compare that with the other VMs 

Hello,

I'm going to try something, the NIC's settings haven't been changed for a while but I installed another software Backup agent on the 10th May for a trial run which was about the time it started going slower.

I've uninstalled it and i'm going to see if that's what the issue is.

I'll keep this posted updated, thanks.

James

Hiya,

Tried my theory and that didn't work, i've attached the job logs with the speed differences.

Kind regards,

James

Gurvinder
Moderator
Moderator
Employee Accredited Certified

</end_time><summary><misc>Backed up 638033 files in 295504 directories.</misc><new_processed_bytes>Processed 249411455273 bytes in  2 hours,  50 minutes, and  24 seconds.</misc>

<new_processed_bytes>Processed 249552631963 bytes in  6 hours,  8 minutes, and  2 seconds.</new_processed_bytes><vlm_hist_rateformat2>Throughput rate: 647 MB/min

the data doesnt seem to have changed to cause the slowness.

https://www.veritas.com/support/en_US/article.100024031  (disable TCP chimney and TCP offload, RSS )

(below are some points from this technote. Can also test the same backup to Disk ( E drive backup because this is where the time has increased maximum because of the backup set size)
 Backup of Remote Server (One or All) to B2D runs at a normal throughput rate in most instances, but runs slower in some network configurations.
 Backup of Remote server (One or All) to tape is consistently slow or loses connection all together during a backup or restore.

Hi,

The link doesn't appear to work :-(.

I did run a BSD job which went to a to a Freenas box, completely different physical server and backup device, so it was over the network again and the speed was the same.

So is it something to do with the backup sets then?? How do i adjust those and what sizes should they be?

kind regards,

James

 

Gurvinder
Moderator
Moderator
Employee Accredited Certified

disable RSS, NETDMA, Chimney, offload as per (On BE server) and test the backup https://support.microsoft.com/en-in/help/951037/information-about-the-tcp-chimney-offload-receive-si...

 

Ok thank you, I've managed to disable the above and i'll check the backup and see what happens.

I don't remember enabling these if this is the problem though.

Thanks,

James

Hello,

I've disabled the above on the Backup server but sadly doesn't appear of done anything?

Anything else I can try?

Thanks,

James

Gurvinder
Moderator
Moderator
Employee Accredited Certified
Is there any snapshot on the VM because of which the backup performance got affected ?

No i don't there is :( :-(.

The host server has 4x nics that a teamed together and 2 of them have a limited status for some reason.

Do you think it could be something to do with that??

Thanks,

James