Advice needed on backup with snapshots

[s88urd85]

Hi all,

Just after a bit of advice really and what is/isnt supported as such.
We have a number of VM's which have patching schedules, and part of this process is to snapshot the VM.
These snapshots can be left on the machine for up to 4 days, meanwhile Veeam backs up these VM's daily.

We have noticed that after the patching snapshot is removed, the next veeam backup will take an awful log time (I presume this is due to the changes being written back to the parent VMDK)

My question is, if Veeam backs up a VM while it is running on a snapshot (which is not the Veeam snapshot) when we try and restore, what state will the VM be in?
Will it have any of the changes which are contained within the child snapshot disk, and if we attempted to do a full vm restore would it have just the parent VMDK (without any of the snapshot changes in)

Thanks

[coolsport00]

This is a great question @s88urd85 -
We had a similar discussion in the Community Hub (see here: https://community.veeam.com/discussion- ... -data-4663). I didn't think Veeam backed up all the data in snaps because Veeam does not back up snapshots. One of the posters confirmed after backing up a VM with snapshots, Veeam somehow still backs up the change data, even though they don't back up snapshots. I do know that yes...when you have snaps on VMs, it does take Veeam a while to do its processing on the 'Collecting disk files location data' step. It would be nice to hear what a PM has to stay & provide the technical details what Veeam does to VMs and their data when they have snapshots. And, if the explanation isn't too deep, would be nice to add the information to the User Guides.
Cheers!

[s88urd85]

Hi @coolsport00
Thanks for the reply.

I did test some FLR restores with this situation.
Created VM Snapshot
Created file on the VM
Performed veeam backup
Removed Snapshot

When i initiated a FLR restore the file I created was there, so it does confirm that veeam backs up the changes while a snapshot is already present.
In a VM file restore however I would expect to see the child (snapshot delta disks) aswel as the parent ones, but this isnt the case, you only see the base disks so i am somewhat confused.

[coolsport00]

@s88urd85 -
You actually shouldn't expect to see the snaps because Veeam doesn't back them up. They explicitly say that in their User Guide documentation. See points 7 & 8 here:
https://helpcenter.veeam.com/docs/backu ... ml?ver=120

Still, as you tested as well as 1 of the poster's in the Community Hub thread did too, Veeam does get the change data somehow. Wish I could tag a PM in these comments to get their take

[jsprinkleisg]

Particularly if you're using Veeam's Backup From Storage Snapshots feature, having a VM snapshot open during the backup job can make the backup process take much longer. So this is a good reason VM snapshots only for very short-term use cases, and ensure they are deleted prior to the backup window. As part of your patching process, consider using Veeam's Quick Backup feature to provide these one-off restore points instead of using VM snapshots.

[karsten123]

In case of an active snapshot, the delta disk becomes the active disk file. As veeam takes a hypervisor level snapshot, it takes it for the active delta disk and backups the data from it. Pretty easy and no voodoo.

[s88urd85]

Particularly if you're using Veeam's Backup From Storage Snapshots feature, having a VM snapshot open during the backup job can make the backup process take much longer. So this is a good reason VM snapshots only for very short-term use cases, and ensure they are deleted prior to the backup window. As part of your patching process, consider using Veeam's Quick Backup feature to provide these one-off restore points instead of using VM snapshots.

Thankyou for the suggestion, the only problem with this would be the delay in restoring from the backup.
With a VM Snapshot the rollback would be pretty quick, however some of these VM's are quite large, so could take a while to restore (unless we use quick rollback)
It certaintly has given me food for thought and a potential workaround, so appreciate your input

[dueni]

Hi
A great add on would be to use a hardware snapshot instead; of course if you have a storage array which supports it: Then you even have a sudden restore instead of wait for a VMware snapshot to be returnded back
regards, dueni