Backup and/or snapshot only the boot disk of a virtual machine.

JanP

Hello,
I have truenas running on a virtual machine.
As data disks I have linked two 8TB disks via passthrough in a mirror configuration.

I would like to take occasional snapshot and backup just the boot disk. Not those 8TB disks.

The question is actually is it possible to exclude this passthrough disk from the snapshot and backup?

olivierlambert

So, in short:

It wasn't possible to call VM.snapshot while excluding a disk in XCP-ng API (XAPI).
So we managed to contribute to it upstream to add this possibility (see https://github.com/xapi-project/xen-api/pull/4563)
This has been merged and will be available in next XCP-ng release (8.3)
It's already implemented on Xen Orchestra side, so as soon we got 8.3 out, [NOBAK] will exclude disks to do the snapshot, and it should work in your case

benjamreis opened this pull request in xapi-project/xen-api

closed Add `ignore_vdis` to `VM.snapshot` method #4563

JanP

@olivierlambert

Ok that sounds good. Do I understand correctly that this is then possible not only for snapshots but also for backups?

olivierlambert

Backup are relying on snapshots, so yes

tjkreidl

@olivierlambert Interesting... this has been possible for some time now using "xe vdi-export" and "xe vdi-import" to be able to choose a particular disk to back up or restore. I guess it just wasn't implemented yet in the management interface?

olivierlambert

Yes, but when you do a disk snapshot, you don't backup the whole VM, just the disks. VDI snap won't trigger the VSS capabilities that you have with VM.snapshot, that's why we needed to implement a VM.snapshot feature with disk exclusion

tjkreidl

@olivierlambert Of course, but that can be done by cloning the VM and detaching all its disks, and backing up that duplicate VM. In addition, then one needs to back up the selected VDI of the boot disk.
Yes, more involved, but possible!

olivierlambert

Not really, because if you have disks that can't be snapshot/cloned (like raw drives), then you won't be able to do it at all.

That's why the best approach is to extend VM.snapshot with disk exclusion, as we did

JanP

@olivierlambert Is there a date known when 8.3 will be released?

olivierlambert

The first alpha ISO is just a matter of weeks.

JanP

@olivierlambert Hello Olivier, Another year since the question. Time flies By now, do you know the eta of version 8.3? And is it still an option in that version to be able to backup only the boot disk.

Kind regards,
Jan

olivierlambert

You can already use the 8.3 beta 1 We might have a release before the end of the year though.

JanP

Ok. Great I wait for the release. Thanks