Server virtualization has crossed the proverbial chasm. Not long ago, when deploying new servers, one had to justify making them virtual, rather than physical. Now, IT managers in many organizations have decreed “virtual first” policies, requiring new server deployments to be virtual unless there is specific justification for a physical server. Alas, for all its goodness, virtualization creates a number of new storage and data management issues. One big problem area is backup. Backup techniques from the physical server world don’t work very well in a VM environment. Why?