If you have tried to start, restart, or stop a container, and you get this err:
vzctl stop 104
Container already locked
You need to do one or both of these commands:
rm: remove regular file `/vz/lock/104.lck’?
vzctl chkpnt 104 --kill
This will delete the lock file, and clear the check point. Once you have run them, you can re-run your vzctl stop/start/restart command.