Any operation on a VE gives me “Cannot lock VE“.
VE is locked when some operation (backup, migration, start / stop, etc.) with this VE is in progress. You can determine which process is holding VE #111 using the following command on the hardware node:
# cat /vz/lock/111.lck
You can kill that process if needed. Make sure that the process is really killed. If there is no process with that PID on the node, just remove the lockfile.
# kill 16824
# vzctl start 111