Host-based backup of Microsoft Hyper-V VMs.
Post Reply
jdixon
Novice
Posts: 8
Liked: 1 time
Joined: Nov 23, 2016 4:30 pm
Full Name: Jacob Dixon
Contact:

Veeam 9 causes high write latency on SSD SAN

Post by jdixon »

We have a Hyper-V cluster with that is connected with 2-paths per server with 8GB fiber to a 3PAR 8200 (we have all 12Gbps SAS SSD). We noticed that for some reason we started getting alerts from Veeam One about very high write latencies when backups have occurred. Now when we were on our 3PAR 7200 10K SAS we didn't seem to have this problem.

We have narrowed it down to backups with Veeam causing this but we have not had a chance to narrow down if its the fiber channel HBA's that are the issue or the SAN itself. I find it hard to believe it the SAN because we cannot be pushing that amount of throughput because of the limitation with the fiber channel is less than the storage.

Has anyone else had this issue?
Gostev
Chief Product Officer
Posts: 31457
Liked: 6647 times
Joined: Jan 01, 2006 1:01 am
Location: Baar, Switzerland
Contact:

Re: Veeam 9 causes high write latency on SSD SAN

Post by Gostev »

As a first step, just enable Backup I/O Control to keep datastore latency at the desired level. Alternatively, you can simply reduce backup or repository proxy slots, as most likely you are just throwing too many concurrent tasks at your SAN.

Then, I recommend opening a case with HP, as I find it quite strange that SSD SAN struggles with our workload when HDD SAN does not (I'd expect the opposite).
jdixon
Novice
Posts: 8
Liked: 1 time
Joined: Nov 23, 2016 4:30 pm
Full Name: Jacob Dixon
Contact:

Re: Veeam 9 causes high write latency on SSD SAN

Post by jdixon »

I thought i fixed it by modifying the queue depth on the HBA on the servers.. but I still see high latency sometimes with 2x8Gbps paths. Haven't found how to limit the I/O control yet
foggy
Veeam Software
Posts: 21069
Liked: 2115 times
Joined: Jul 11, 2011 10:22 am
Full Name: Alexander Fogelson
Contact:

Re: Veeam 9 causes high write latency on SSD SAN

Post by foggy »

Andreas Neufert
VP, Product Management
Posts: 6707
Liked: 1401 times
Joined: May 04, 2011 8:36 am
Full Name: Andreas Neufert
Location: Germany
Contact:

Re: Veeam 9 causes high write latency on SSD SAN

Post by Andreas Neufert » 1 person likes this post

Another customer had an issue with ODX and the Storage.

Deaktivation of the SSD trim helped in that case. Please check with Microsoft Support if this is the case.

The solution was the following reg key:
Set-ItemProperty hklm:\system\currentcontrolset\control\filesystem -Name "DisableDeleteNotification" -Value 1
Post Reply

Who is online

Users browsing this forum: No registered users and 24 guests