"The need to consider power and cooling alongside virtualization is becoming more and more important," he says. "If you just virtualize, but don't alter your infrastructure, you tend to be less efficient than you could be."

4. Virtualization makes me safer

The ability to clone VMs and move them from one physical box to another opens up great possibilities for disaster recovery -- and that in turn protects your business from data loss and downtime. But virtualization, if not managed properly, also brings new security risks that could threaten the safety of data and continuity of business systems.

People and processes are often not ready for virtualization and the it introduces, IBM security expert Joshua Corman has argued.  

Virtualization brings new attack surfaces and various operational and availability risks. Consolidating many applications onto a single server "gives you a single point of failure," DiDio notes.