Professional Xen® Virtualization

Chapter 4. Booting and Configuring a Xen Host

Now the fun actually begins! The previous chapters provided background information on virtualization in general and Xen in particular, and discussed how to obtain and install Xen on a Linux system. In this chapter, we finally get to start the Xen hypervisor and boot a paravirtualized Linux kernel under the hypervisor. By the end of this chapter, you'll have a fully functioning administrative domain for Xen (domain0) and will be ready to move on to installing paravirtualized Xen virtual machines and/or fully virtualized Hardware Virtual Machines (HVMs) in your Xen environment, depending upon the capabilities of your hardware.

As in the rest of this book, this chapter focuses on using Xen on Linux systems. Therefore, this chapter focuses on the Xen hypervisor boot process, which is essentially the same on any system, and subsequent interaction between the Linux boot process and Xen domain0 initialization. If you are booting Xen on a Solaris or *BSD system, the startup process will be similar and will perform the same types of tasks, but systems other than Linux are not covered in detail in this chapter.

Overview of Xen and Linux System Startup

As discussed in the previous chapter, the standard Linux boot loader, known as the Grand Unified Bootloader or GRUB to its friends, is a key component of installing and booting the Xen hypervisor on a Linux system. GRUB not only understands how to boot the Xen hypervisor like any other bootable image, ...