'''Note:''' if you use kernel >= 3.10.0-327.18.2.vz7.14.25<= kernel <= 3.10.0-327.28.2.vz7.17.5, you need to allow using "overlayfs" inside a Virtuozzo Container:

This is was a temporary step, it will be dropped once if you use kernel >= 3.10.0-327.28.2.vz7.17.6, overlayfs is proved to can be absolutely safe to run in any vz7 used inside a Containerby default.