vzctl mount XXXX
Opening delta /vz/private/XXXX/root.hdd/root.hdd
Adding delta dev=/dev/ploopXXXX img=/vz/private/XXXX/root.hdd/root.hdd (rw)

/dev/ploop15649p1: UNEXPECTED INCONSISTENCY; RUN fsck MANUALLY.
(i.e., without -a or -p options)
Error in e2fsck (fsutils.c:288): e2fsck failed (exit code 4)

Failed to mount image: Error in e2fsck (fsutils.c:288): e2fsck failed (exit code 4)
[41]

ploop check -F /vz/private/CID/root.hdd/root.hdd
ploop mount /vz/private/CID/root.hdd/DiskDescriptor.xml
fdisk -l /dev/ploopXXXXX
e2fsck -y /dev/ploopXXXX

ploop umount /vz/private/XXXX/root.hdd/DiskDescriptor.xm