Proxmox6 VM backup causes Windows VM to lockup

[adamb]

Hey guys we recently started moving our production clusters to proxmox6. Everything has been going really well except for when we backup our 1 and only Windows Server 2012 VM. It causes this VM to lockup and we have to reset it via the proxmox GUI.

All of our linux VM's and Windows 10 VM's are backing up without issues so I am at a bit of a loss.

We do have this VM set to "Microsoft Windows 8.x/2012/2012r2" and because its an older install its still using the LSI 53C895A SCSI controller. The few windows 10 VM's we have are newer and are using the Virtio SCSI controller.

Should I look to move this VM to Virtio? Are there any other known issues I could be missing?

 

[Dominic]

Using VirtIO generally works with Windows Server 2012 (see our best practices).

Do you have detailed logs of what happens when your lockup occurs?

 

[adamb]

The move to Virtio has resolved this issue. No more lockups during backups.

 

[Dominic]

Great that you could solve your problem! It would be great if you could mark the thread as resolved by editing your opening post so that others know what to expect.

 

[adamb]

Great that you could solve your problem! It would be great if you could mark the thread as resolved by editing your opening post so that others know what to expect.

Actually I take that back, I was just made aware that it locked up again during the backup.

When you say detailed logs, what do you mean? Windows side or proxmox side?

 

[FLVS-Nick]

Did you ever find a resolution to this? My 6.x cluster is doing the same thing. We've got 2 windows 2012 VM's that do the same thing. But some that don't. We've also had a RHEL VM from a vendor randomly re-enable IP tables every time the backup is run.

 

[Dominic]

Could you please post the following?

• output when you run the backup
• syslog of the relevant time
• VM configuration qm config <vmid>

Lockup = you just can't see anything in the VM moving? What is the resource usage of the VM processes?