Today, virtualization is emerging as the fastest way to help businesses with scalability, security and management of their global IT infrastructure. Virtualization is a set of technologies that helps IT run more applications on a given set of servers, can dramatically increase utilization of existing capacity and could enable businesses to leverage their current hardware to meet their needs for years to come. This facilitates IT to make immediate, incremental changes to capacity to meet dynamic business needs without incurring new costs. But performance penalty is an inevitable result of the traditional approach to implementing virtualization.
I have read an interesting white paper on virtualization and its benefits in avoiding the performance penalty from BEA. The white paper is available at the following link.