Ubuntu server issue after backup

[ccnet]

Hi,

Config :
Ubuntu 22.04.5 LTS vm on PVE 9.2
PBS 4.2
Qemu agent installed in option.
Qemu agent running on the vm, tested with "systemctl status qemu-guest-agent"
qemu agent 10x ping is working
In Hardware SCSI Controler is "LSI 53C895A"

Issues
Logs :
112: 2026-09-13 19:07:33 INFO: skipping guest filesystem freeze - agent configured but not running?
112: 2026-09-13 19:07:33 INFO: starting backup via QMP command
112: 2026-09-13 19:07:34 INFO: started backup task '8f82487a-604d-48b3-8d0c-e761c1888196'
112: 2026-09-13 19:07:34 INFO: resuming VM again112: 2026-09-13 19:07:34 INFO: scsi0: dirty-bitmap status: OK (drive clean)
112: 2026-09-13 19:07:34 INFO: scsi1: dirty-bitmap status: OK (drive clean)
112: 2026-09-13 19:07:34 INFO: scsi2: dirty-bitmap status: OK (drive clean)

But cannot login on the vm. Keyboard freeze.
I need to force a restart with Stop, Shutdown don't work.
After reboot i have to manually restart samba4 service because shared folder are no more working.
When the vm start qemu agent is started.

Change SCSI Controler to VirIO SCSI can solve the problem ?
Some others Ubuntu vm don't have issue after backup.
Thanks in advance.

 

[ccnet]

I've forgot: backup mode is snapshot. Mode "Stop" don't solve the problem.

 

[Chris]

Check the VMs systemd journal for errors related to the qemu guest agent. Further, you might want to consider using backup fleecing https://pve.proxmox.com/pve-docs/pve-admin-guide.html#_vm_backup_fleecing

 

[ccnet]

Check the VMs systemd journal for errors related to the qemu guest agent. Further, you might want to consider using backup fleecing https://pve.proxmox.com/pve-docs/pve-admin-guide.html#_vm_backup_fleecing

Thank ypu Chris. I let you know.