Instant Recovery Speed

[jayk]

I am currently testing the instant recovery feature in B&R. I have Veeam, and Hyper-V installed on the same physical server. The backup repository is also local storage on the same physical server. I created a server 2012 test VM and installed SQL Server.

The instant recovery job is reasonably fast, it takes about 20 seconds. However the server takes over 10 minutes to boot into Windows. Once logged in everything is very sluggish for about 5 more minutes, then normal speeds are observed. What is happening that instant recovery is so slow? Booting the server normally is just fine on this server, I must have something setup incorrectly on the backup or recovery job that is really hurting my instant recovery tests.

[veremin]

So, is it the same storage that is used for storing production VMs? Thanks.

[jayk]

No, the production environment is a failover cluster, SAN setup. The Veeam backup server is doubling as a last resort hyper-v host that would be used for instant recovery.

[veremin]

Since it's all-in-one deployment, are you positive that underlying machine isn't deprived on physical resources? Were there any resource utilization peeks during Instant VM Recovery? Thanks.

[jayk]

Only thing I noticed was that the guest and host at 4GB of RAM each were utilizing about 85%. I'm going to throw 96GB into that server right now and allocate as much as possible to host and guest(instant recovered) to determine if that was indeed an issue.

[Vitaliy S.]

Do you see the same poor performance (for 5 min) for all VMs you try to use Instant VM recovery feature for?

[jayk]

I was able to do some more testing finally. It is happening with all the VMs I try to instant restore. I installed the 96GB of ram to determine if it was a memory issue. I allocated 32GB to a fresh install+backup VM of server 2012. It ran just as horrible as when it only had 4GB memory in my original test. I did notice another oddity on the physical machine. When the instant recovery is starting, and the VM is booting, my network I/O fully saturates just under a gigabit. There are two VeeamAgent.exe's (one sending ~450Mbit, one receiving ~450Mbit). Not sure why there's network activity in this scenario, but nothing else in the resource monitor appears to be a bottleneck.

[Vitaliy S.]

The main thing to consider while using Instant VM Recovery is the performance of the repository where your backups are stored. The more IOPs it can provide, the better.