Backing up a Windows VM with Microsoft VSS enabled

[DrWhy]

Is there any known limitations when taking a backing up of a Windows 2012R2 VM (or any Windows VM for that matter) when VSS is enabled within the VM and the VSS storage location is on a different volume? I come from a Hyper-V environment, where the Hyper-V snapshot providers were not able to support this. I wasn't sure if it was the same with VMware. We are running vSphere 6 (and yes it has the latest patch that fixes some VSS issues).

[dellock6]

Not sure I follow you here, VMware has no VSS libraries at the storage layer, but used different technologies. VSS is only available inside the VM for application consistency.

[DrWhy]

Maybe this will help. Consider this scenario: Within a guest Server 2012R2 VM, I right click a disk in my computer. I select "Configure Shadow Copies". I then select Enable for a volume. I then click settings and change the storage area and set it to be located on a different drive letter. In this scenario, Hyper-V cannot backup the VM in an application consistent state, it must suspend the VM while it takes the backup. I'm wondering if there are any gotchas, drawbacks or things that I should be aware of when backing up a VM that is configured like this.

[Vitaliy S.]

If you're able to create a VSS snapshot manually in the guest OS, this should be sufficient for Veeam to enable AAIP and run the job. Thanks!

[DrWhy]

I'm not asking if Veeam can use this as a snapshot. I'm asking, if I have these snanpshots configured and scheduled within the guest OS, if Veeam will have any problems backing up in the VM.

[Vitaliy S.]

Ok, got it. Definitely no issues with AAIP option disabled, also I don't see how existing VSS snapshots can interfere with our AAIP process and backup job itself, but I will double check with our QC team tomorrow.

[DrWhy]

Thanks Vitaley

[Vitaliy S.]

Just talked to our QA team. There should be no issues, but keep in mind these things that could affect your backup job:

1. Guest OS VSS snapshots creation (if they are scheduled) should not overlap with your backup job
2. You need to monitor the diff area size (VSS storage location), cause if you run out of free space for your diff area, VSS snapshots might be dropped/consolidated.

Other than these two, you should be ok doing backup jobs without VM suspension task.

[DrWhy]

That's great, thank you for this information. What is a VM suspension task?

[Vitaliy S.]

I was referring to your quote, just a rephrased version.

In this scenario, Hyper-V cannot backup the VM in an application consistent state, it must suspend the VM while it takes the backup.

[DrWhy]

Oops, my mistake. That makes sense. Thanks again!
On a different note, would it be possible for you to comment on my question found here:
http://forums.veeam.com/vmware-vsphere- ... 81-15.html

I haven't heard back from anyone in over a week and would really like to get my question answered.

[Vitaliy S.]

Sure, let me look through your thread.

[DrWhy]

Thanks Vitaliy. I just posted a more comprehensive post here. Please review this post instead.

http://forums.veeam.com/vmware-vsphere- ... 28233.html