OpenVZ container cannot start on the SolusVM slave node: e2fsck failed (exit code 4)

Symptoms 

• OpenVZ VPS does not start - it stays offline in SolusVM > Virtual Servers > VPS
• When trying to start the VPS manually on OpenVZ node the following error is displayed:

  # vzctl start 101
  Starting container...
  Opening delta /vz/private/101/root.hdd/root.hdd
  Adding delta dev=/dev/ploop11111 img=/vz/private/101/root.hdd/root.hdd (rw)
  /dev/ploop11111p1: UNEXPECTED INCONSISTENCY; RUN fsck MANUALLY.
  (i.e., without -a or -p options)
  Error in e2fsck (fsutils.c:293): e2fsck failed (exit code 4)
  
  Failed to mount image: Error in e2fsck (fsutils.c:293): e2fsck failed (exit code 4)

Cause

File systems of the VPS is corrupted.

Resolution

1. Connect to the OpenVZ node via SSH
2. Backup the affected VPS
3. Check the container device with ploop command:

   # ploop check -F /vz/private/VMID/root.hdd/DiskDescriptor.xml

4. Remount the VPS image and note the ploop device path:

   # ploop mount /vz/private/VMID/root.hdd/DiskDescriptor.xml
   Opening delta /vz/private/VMID/root.hdd/root.hdd
   Adding delta dev=/dev/ploop56824 img=/vz/private/VMID/root.hdd/root.hdd (rw)

5. Repair the 1 partition of ploop device from step 4 with e2fsck tools:

   # e2fsck /dev/ploop56824p1 -y