If you need an affordable and stable solution to offer high availability for virtual machines, this book is written for you. With this book you will learn how to build an HA solution with open source software. The solutions described in this book can help our organization save thousands of dollars on data center virtualization. You will learn how to create virtual machines using Xen and how to make them highly available using Pacemaker software. As a bonus, you will also read how to implement a cheap SAN solution, using open source software. This book is written for anyone who wants to create an affordable and stable solution for high availability of Xen virtual machines. To get the most out of this book, the reader should have a good working knowledge of Linux. The book uses SUSE Linux Enterprise as the example distribution. The configuration is also applicable to other distributions.