Slow vm restores
Running NBU 8.1 on Server 2016, restoring a vm from MSDP direct to Compellent SC4020 SAN we are underwhelmed with the performance. We see KB/Sec 18713. We get similar performance when using LAN trans...
Forum Discussion
What is your backup speed?
Have you tried to play with buffer size and number for the restore?
Could you share your current buffer values?
Did you try to restore the VM to another place? You wrote that you had the same speed using LAN and it's very slow even for LAN. May be your Storage is experiencing performance issue? Do you have another ESX/Datastore?
Do you have same restore speed for another VMs? Because it might be a problem with particular VM. Try to restore another VM at the same DataStore but with different name and without NIC.
Thank you both for your replies.
Marianne Indeed, SAN restore does appear to offer the poorest performance. We saw KB/Sec 35003 when using HotAdd, which is an improvement however still not satisfactory. We did try a "thick" SAN restore but only achieved KB/Sec 31887.
Mike The fastest backup rate we have achieved so far is KB/Sec 198041 and this was a SAN backup using NUMBER_DATA_BUFFERS = 1024. We have been playing around with buffers and although these appear to have great effect on backup performance, we do not see the same gains with restores. We have SIZE_DATA_BUFFERS_DISK = 1048576.
We have tried various combinations of restores to different environments / datastores / storage / ESX servers. We confirmed with Steelbytes utility that we have a read speed of 1GB/Sec on the MSDP storage.
As said, we are reasonably happy with backup performance just not restore. It seems that the buffers have little or no effect on restore speeds. We also triued a restore with removing the NIC but saw no improvement.
Could I ask you both what sort of performance you have seen when restoring vm's?
I think I'll raise a ticket with Veritas support.
Thanks for your help,
Graham
Another TN with possible reasons for slow VMware restores:
https://www.veritas.com/support/en_US/article.TECH169860
According to this doc, expected restore speed (because of the way VMware APIs works) is about a third of backup speed.
So, best to log a call with VMware as well.
Update! We previously only tested "Lazy" thick provisioned restores. We tried a "Eager" thick restore and achieved KB/Sec 81390 which is much better - but still not fantatastic! The more I read the more I think it might actually be vmware throttling it. This is an interesting read albeit for a rival product!!
Thanks for all your help guys.
Graham
