Not sure what update caused this or when, but the latest vzctl package update changes the storage default from simfs to ploop.
You may be in for a surprise when things go screwy if you don't have ploop support enabled in solusvm.
Fix is setting VE_LAYOUT="simfs" in /etc/vz/vz.conf. No vz service restart needed.
I checked openvz.org and nothing was posted regarding this change.
Just giving everyone a heads up as this screwed with us a bit.