Backup/Restore: Problems with saving state on one of the two virtual harddisk while making backup.

[anton5000]

Hi all,

I have a recent installation of Proxmox 6.4-4/337d6701 with one VM. This VM has two Virtual disks (C and D that are stored on two different pools. On the VM I have Windows 2019.
When I make backup in snapshot or stop mode, it seems that one of the disks, in this case (C does't lock/freeze the state of the file system before backup starts. That means while backup is running changes are being written on the harddisk. At first I didn't understood what was happening after the recovery. Some files on C: disk where newer then the files when the backup has started. That is not the case on a second (D Virtual hdd. Then I run many tests including unpacking large zip file on both disks after starting backup. On the second (D disk I get pre-backup state as it should but on C: I get unpacked archive after restore. Then I tried to backup just one C: disk and there I get pre-back state after restore as it should be. So my conclusion is that while making backup of a VM with two disks one disk doesn't get pre-backup state as it should.
Is it a bug or there is something wrong with configuration?
At this moment to get a consistent backup I need to shutdown VM and then make the backup.

 

[floh8]

u use zfs, so snapshot have to work

 

[anton5000]

u use zfs, so snapshot have to work

Hi, thanks for your reply. Yes, this is what I thought, but after few recovery tests I noticed that some files are inconsistent. Then I startet to test more and dig deeper. After more tests I discovered that only one disk of the two gets a consistent snapshot.

 

[floh8]

if use snapshot than all device have to support that. dpool ist not zfs i think

 

[anton5000]

if use snapshot than all device have to support that. dpool ist not zfs i think

Dpool is ZFS as well. Basicly when I backup local and dpool together I get only snapshot on dpool. But, when I deattach dpool and make backup only with local pool then I get snapshot on my local pool. Strange...