PBS Limit or Exclude VM Volume

[TechBrain64]

Is there a way to limit or exclude partitions/volumes/folders/files while backing up a VM? If so, please elaborate.

 

[fabian]

no, the VM backup happens on a (virtual) disk/block level, only full disks can be included or excluded.

 

[TechBrain64]

@fabian,

Thanks for your response. Given what you've explained, how would I exclude virtual disk vm-200-disk-1 while still backing up vm-200-disk-0?

 

[fiona]

Hi,
there is a Backup checkbox in the advanced settings when editing the disk in the VM's Hardware view in Proxmox VE.

 

[TechBrain64]

@fiona,

Thanks, that seems to be what I'm looking for. However, just to be thorough, will this still work if the disk is mapped as a mount point under /mnt or any other folder?

 

[TechBrain64]

@fiona / @fabian

I just confirmed the backup does indeed exclude the mount point disk. I have a virtual instance of TrueNAS Scale with passthrough disks which I wanted to exclude from the backup.

Thanks for the assistance.

 

[VictorSTS]

The disk will not be included in the backup if Backup isn't ticked.

Be very careful when restoring that VM: if restoring to the same VMID, the restore will remove the VM, deleting the non-backed-up disk. Then, only the backed up disks will be restored. That means that you may lose some hopefully unimportant data and also that you should add that disk to the VM configuration. Depending on the VM OS and configuration, it may not even boot (i.e. Linux with a drive mount on /etc/fstab set as auto). Practice with some test VMs.

 

[fiona]

The disk will not be included in the backup if Backup isn't ticked.

Be very careful when restoring that VM: if restoring to the same VMID, the restore will remove the VM, deleting the non-backed-up disk.

This is only true for owned mount point volumes of containers, because containers are backed-up and restored as a whole file-system at the moment. For a VM, only disks that are part of the backup will be removed during restore (based on the drive key, i.e. if the backup includes scsi1, then the current scsi1 disk will be removed). Others are kept as unused disks.

Then, only the backed up disks will be restored. That means that you may lose some hopefully unimportant data and also that you should add that disk to the VM configuration. Depending on the VM OS and configuration, it may not even boot (i.e. Linux with a drive mount on /etc/fstab set as auto). Practice with some test VMs.

 

[VictorSTS]

Thanks! It's been ages since I last tried it, but it behaved like that in the past.

 

[TechBrain64]

@VictorSTS

The TrueNAS Scale VM is the target storage for other LXC containers/VMs which have their own backups. I just wanted to get the NAS/OS backup. I will ensure if needed to restore to alternate VMID and remap drives to it.

 

[fiona]

Thanks! It's been ages since I last tried it, but it behaved like that in the past.

Are you sure, you're not thinking of containers? There it is the case and they warning in the UI was improved 1 or 2 years ago, because it can be unexpected.

Because for VMs, the logic was there since 2013 with commit ed221350 ("vma restore: only delete disks contained in backup."): https://git.proxmox.com/?p=qemu-ser...d;hp=19168b91ae543aa6e4dede2f10b705ca0f07990f

 

[TechBrain64]

@fiona / @VictorSTS

So, then a restore will only restore the disk which was backed up, leaving the pass-through disks for remapping?

 

[fiona]

@fiona / @VictorSTS

So, then a restore will only restore the disk which was backed up, leaving the pass-through disks for remapping?

Yes, you'll have to re-attach a passed-through disk manually after restore.

 

[bcart167]

Sorry, I'm a bit dense - I'm in the exact same scenario: I have TrueNAS in a VM and I want to back it up because the update from 7 to 8 says I should back up my VMs. But when I go to back it up, the only option I get is the whole VM including the passthrough disks and it tries to back up 20TB which I don't want. I only want to backup the VM. Where do I go to exclude the passthrough disks? Or are you saying remove the disks, do the backup and reattach after a backup?

EDIT: Nevermind, I have found it! Thank you. See? Told you I was a wee bit daft. lol