Virtualization is not new. IBM first introduced virtual machine technology for mainframe computers in the early 1960s. Microsoft Windows NT included a virtual DOS machine. Virtual PC was introduced by Connectix in 1997 (Microsoft acquired Connectix in 2003). EMC’s VMware introduced its first product, VMware Workstation, in 1999. Softricity introduced SoftGrid, the first application virtualization product, in 2001 (Microsoft acquired Softricity in 2006). Server virtualization is the masking of server resources, including the number and identity of individual physical servers, processors, and operating systems, from server users. The server administrator uses a software application to divide one physical server into multiple isolated virtual environments. The virtual environments are sometimes called virtual private servers, but they are also known as partitions, guests, instances, containers or emulations. There are different types of virtualization. Machine virtualization uses softwar...