Backup Causes Remove Snapshot that Freezes VM?

[davidshq]

We have a Linux VM running on ESXi, there are numerous other Windows/Linux VM's on this same machine that we also backup. When we backup this particular VM (lets call it VM1) it freezes the VM while VMWare ESXi says it is doing a "Remove snapshot." This happens basically every time we run the backup on this machine. Why is it locking out our vm? How can we stop this from occurring?
Dave.

[Gostev]

Dave, Veeam Backup is no different from VMware Infrastructure Client when working with snapshots (we use the same API). Snapshot removal creates disk I/O congestion because snapshot files are commited into the main VMDK file - this may result in some freezes depending on how much changes need to be commited. Unfortunately this is how snapshots work. Thank you.

[davidshq]

Is there any way to allocate more resources to cleaning up these snapshots faster? So it doesn't take as long?
Dave.

[Gostev]

Dave, to my understanding the time it takes to commit snapshot mostly depends on the speed of your VM storage (since this operation is about doing a lot of reads from snapshot file and writes into random locations througout the flat VMDK file).

[davidshq]

Okay, I was just wondering, b/c I saw over on an esXpress forum the following thread which indicated that change some system resource allocations could alleviate the issue but didn't want to start messing with these values unless it would really make a difference:
http://support.esxpress.com/boards/read.php?1,3468

[Gostev]

I believe esXpress requires this mod due to their architecture. While most of their code is indeed running inside of a virtual appliance (as they like to advertize), they also rely on pretty heavy service console agent to perform some operations that (I assume) cannot be performed from within VA. This agent is also the reason why they do not (and cannot) support ESXi.

Again, just want to stress that Veeam Backup uses remote VMware API to perform all snapshot operations (same API that is being used by VMware Infrastructure Client). So, similarly to how you do not need to increase you ESX service console memory in order for VMware Infrastructure Client to be able to manage snapshots of your ESX host, you do not need it for Veeam Backup either.

[davidshq]

Okay, thanks. I've had to remove the vm from the backup routine for the time being until we can come up with a solution...as it is freezing daily and sometimes needs the entire physical machine rebooted to bring it out of it. But the rest seem to be backing up okay.
Dave.