I have a demand here to add a server to our branches, this server have a prebuilt image, and is recommended to run as a VM.
We have OES 11 running on these branches, as physical machines.

I know that I can install OES over Xen or KVM, but these OES servers are already installed, I cannot just move them to Xen or KVM (and the hardware running them is known to have issues with Xen).

My question is, is it possible (or safe) to run a full virtualization infrastructure, like virtualbox, qemu or vmware server ontop an OES 11 server?