maximum number of simultaneously Instant recovery sessions

[sandsturm]

Hi

Is there a maximum number of simultaneously Instant VM recovery sessions on a Veeam Backup server? I'm implementing a solution to do automated restore tests and the process starts instant recovery sessions of the VMs and I'm wondering where the maximum number of simultaneously Instant VM recovery session is?

thx
sandsturm

[PetrM]

Hello,

There is no hard-coded limit for the maximal number of simultaneous Instant Recovery sessions. The appropriate number of parallel restores can be different in different environments, you should define this number in your specific case during restore tests. For example, you can start with 10 sessions and gradually increase this number.

Thanks!

[foggy]

I don't think there's a limit on the product side, you will likely stub into the storage I/O capabilities at some point.

[sandsturm]

I tried to increase the amount of simulaneous session. It was okay with about 10 session, but now with 17 sessions the Veeam Backupserver is really really laggy. DB Server with the Veeam DB has an unusual CPU load as well. The proxy/repository server looks okay from cpu/mem/disk perspective....

In my opinion, 17 sessions is not really a high number, my idea was to have 40-50 VMs running simultaneously.... but that seems not to be possible.

[Andreas Neufert]

Do you run everything on the same server (Repository role, Mount Server, Backup Server, SQL Server? What are the resources of the server (Cores/RAM/number of disks/...)?

[sandsturm]

No, I have separate servers (all of them are VMs):
- VBR Server: 24vCPUs, 92GB Memory
- DB Server: 16 vCPUs, 200GB Memory (DB server hosts DBs for VBR, vONE and Veeam EM)
- Repo/Proxy/Mount server: 24 vCPUs, 256 GB Memory, repositories (SOBR's) attached via iSCSI to proxy server, provided from a netapp e-series storage system

[Andreas Neufert]

Looks like plenty of resources for this.
Which Veeam Version do you run? v11 made significant changes in the way on how we accelerate processing.

[sandsturm]

latest veeam version is in use

[Andreas Neufert]

OK then someone need to analyse the bottlenecks. I suggest to open a support case and upload logs. I would add in the text a description which servername and IP is has what role so that the collegues can check the data flow.

For the SOBR extents, can you please double check the mount server settings, and at least temporary place it on the Repo Server.
Per instant restore VM disk you need 512MB RAM as read ahead cache. So I would monitor there as well the overall RAM consumption.

Other things that I would check is Antivirus solutions. sometimes they read all data that you touch and slowdown the process. Please check Veeam KB 1999 to see if you have the right Antivirus settings. https://www.veeam.com/kb1999

[Kaiutin]

Hi,

There is no hard-coded limit but is there some limit that could be imposed? Intant recovery for multiple VMs can be destructive and only needed for testing or DR purposes. We don't do this kind of testing and hope to never see a DR scenario that would require the use on more than one instant recovery session at a time.

[Andreas Neufert]

I don´t think that there is configurable maximum number of current instant restore session.
The technology is build for parallelization and the backup target storage performance that goes into higher latency if you overload it is the natural shield for too many sessions.