Chapter 1. Xen—Background and Virtualization Basics

Xen is a virtual machine monitor (hypervisor) that allows you to use one physical computer to run many virtual computers—for example, running a production Web server and a test server on the same physical machine or running Linux and Windows simultaneously. Although not the only virtualization system available, Xen has a combination of features that make it uniquely well suited for many important applications. Xen runs on commodity hardware platforms and is open source. Xen is fast, scalable, and provides server-class features such as live migration. This chapter discusses common uses and types of virtualization, describes the history of virtualization and origins of Xen, provides a brief overview of the Xen architecture, and compares Xen with other virtualization systems.