Symptoms
Container cannot be started with the following error:
[root@vz ~]# vzctl start 101
Mount image: /vz/private/101/root.hdd
/dev/ploop30233p1: UNEXPECTED INCONSISTENCY; RUN fsck MANUALLY.
(i.e., without -a or -p options)
Failed to mount image /vz/private/101/root.hdd: e2fsck failed (exit code 4)
Failed to mount image: e2fsck failed (exit code 4) [152]
Cause
Container's mount fails due to file system errors inside the ploop virtual disk.
Resolution
Run the check disk as per the instructions from the following article
115683 How to perform fsck on a ploop container