Professional Xen® Virtualization

Chapter 2. Introduction to Xen

Virtualization is easily today's hottest IT buzzword, for a variety of good reasons that were discussed in Chapter 1. What's not to like about the idea of reducing costs, making better use of existing hardware resources, and viewing your commodity hardware as a pool of computing resources rather than a set of dedicated, single-purpose machines? This doesn't mean that you can drag out a bunch of aging servers, make a deal with the devil, and suddenly transmute them into a state-of-the-art computing facility. The hardware on which you base your virtualization solution must be sufficiently powerful to run multiple operating systems and server instances simultaneously. Similarly, you must choose virtualization software that supports the way in which you want to use virtualization and provides the power to use virtualization effectively.

This chapter provides a detailed introduction to Xen, discussing its history, terminology, and capabilities, and also identifies the best resources for the latest information about Xen and virtualization on the Internet. It concludes by providing an overview of current virtualization and emulation solutions other than Xen. This "competitive" information shouldn't shake your faith in Xen as the best virtualization technology today, but is instead intended to help you make sense of the zillions of available and emerging virtualization technologies. Not all virtualization solutions are orthogonal—some are quite complementary. ...