TASK ERROR: VM is locked (backup)

jmjosebest

Active Member
Jan 16, 2009
140
10
38
Hi, after a full host restart I get this error starting a virtual machine KVM.

TASK ERROR: VM is locked (backup)

/var/lib/vz/lock is empty...
How can I unlock?
Thanks
 

RollMops

Member
Jul 17, 2014
30
0
6
o.k., unlock works. But how can it be prevented that the VE locks itself up in the first place?I have one that keeps falling into this state, cannot be (re-)started via the web-interface and needs above manual unlock to be (re-)started again. What could be the cause?
Cheers
 

fabian

Proxmox Staff Member
Staff member
Jan 7, 2016
5,025
821
163
find out why the backup job crashed.. is it backing up to unreliable (network) storage?
 

RollMops

Member
Jul 17, 2014
30
0
6
Thank you, Fabian.
So it is definitely a crashed backup-job that prevents the VE from (re-)starting? How could I find out what is the cause of the crash during backup?
Backups are performed on local storage (ZFS pool: rpool)
None of the other 5 VEs on this box has this problem; they are all backed up together once a week.
 

fabian

Proxmox Staff Member
Staff member
Jan 7, 2016
5,025
821
163
check the system logs around the time of the failed backup, try manually backing up the VM a couple of times and check for failure.

it might have been a one time fluke.
 

RollMops

Member
Jul 17, 2014
30
0
6
I can provoke a system crash by manually starting a backup of the VE that I use to find in a locked state.
After 1 or 2 mins., process z_wr_iss takes 97% CPU and subsequently the server fails. It then automatically reboots, but the VE is still locked from the pending/failed backup process and does not automatically recover.
I attach a screenshot of the last state seen in "top".
Could this be prevented by adding some RAM to the box?

Bildschirmfoto 2016-09-28 um 14.41.03.png
 

RollMops

Member
Jul 17, 2014
30
0
6
just a brief follow up: I upgraded my box (hp micro server gen8). RAM from 2GB to 4GB, replaced the Celeron w. an i3. No more problems since then. proxmox' official system requirements state 8GB RAM for a good reason :)
 

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