Using Partitioning and Virtualization Technologies with Windows Server

Use of partitioning or virtualization (virtual machines) technologies with Windows Server may trigger the need to purchase more than one server license for a server machine.

Partitioning divides a server’s processors and other hardware resources into logically separate sections, each with its own OS and applications. For example, a server machine with eight CPUs can be divided into three partitions: the first partition using CPUs 1, 2, and 3; the second partition using CPUs 4, 5, and 6; and the third partition using CPUs 7 and 8. Partitioning is more commonly implemented in hardware rather than software.

Virtualization is a similar concept—it allows multiple OS environments (virtual machines) to run on a server at the same time—except that it does not bind virtual machines to specific CPUs, can be employed on a single-CPU machine, and is typically implemented in software. For example, virtualization software allows a single server to run Windows 2000 Server and Windows Server 2003 in two separate virtual machines, with each running its own set of server applications.