Symptoms

SimFS-based container migrated from OpenVZ to Parallels Cloud Server fails to get converted to ploop:
Cannot mount: /vz/template:/vz/private/CTID/fs /vz/root/CTID: No such device

Cause

Container is migrated from SimFS layout to VZFS.
In case of fresh Parallels Cloud Server installation VZFS layout for containers is disabled and no templates are installed and cached.
Hence mounting the container for convertion to ploop fails.

Resolution

Convert container to OpenVZ ploop format prior to migration:
[root@openvz ~]# vzctl convert CTID