Organizations can correct common problems with virtualization, such as VM sprawl and network congestion, through business policies rather than purchasing additional technology
"Organizations often have to deal with virtualization problems such as VM sprawl, network congestion, server hardware failures, reduced VM performance and software licensing restrictions. But companies can mitigate these issues before they occur with lifecycle management tools and business policies.
Server virtualization brings far better system utilization, workload flexibility and other benefits to the data center. But in spite of its benefits, virtualization isn't perfect: The hypervisors themselves are sound, but the issues that arise from virtualization can waste resources and drive administrators to the breaking point..."