Symptoms
Attempt to stop/unmount a container fails with the following error message:
Failed to stop/unmount the CT: PRL_ERR_VZCTL_OPERATION_FAILED (Details: Failed to umount image: Error in ploop_stop (ploop.c:1165): Can't stop /dev/ploopNNNNN because kernel is in "PLOOP_MNTN_PUSH_BACKUP" state now [46]
Cause
The container in question is locked by the backup process.
Resolution
IMPORTANT! Please note that upon restarting the Dispatcher service, all active VNC sessions on the node will be interrupted.
1. Find the backup process associated with CT
# ps aux | grep CTID root PID 0.0 0.0 112708 976 pts/0 S+ 18:33 0:00 grep --color=auto CTID root PID 0.0 0.0 726416 16588 ? Ssl Oct02 10:44 prlctl backup CTID
2. Kill the backup process:
# kill -9 PID
3. Restart the Dispatcher service:
# systemctl restart prl-disp