Chapter 15. Network Booting with libvirt

Guest virtual machines can be booted with PXE enabled. PXE allows guest virtual machines to boot and load their configuration off the network itself. This section demonstrates some basic configuration steps to configure PXE guests with libvirt.
This section does not cover the creation of boot images or PXE servers. It is used to explain how to configure libvirt, in a private or bridged network, to boot a guest virtual machine with PXE booting enabled.

Warning

These procedures are provided only as an example. Ensure that you have sufficient backups before proceeding.

15.1. Preparing the Boot Server

To perform the steps in this chapter you will need:
  • A PXE Server (DHCP and TFTP) - This can be a libvirt internal server, manually-configured dhcpd and tftpd, dnsmasq, a server configured by Cobbler, or some other server.
  • Boot images - for example, PXELINUX configured manually or by Cobbler.

15.1.1. Setting up a PXE Boot Server on a Private libvirt Network

This example uses the default network. Perform the following steps:

Procedure 15.1. Configuring the PXE boot server

  1. Place the PXE boot images and configuration in /var/lib/tftp.
  2. Run the following commands:
    # virsh net-destroy default
    # virsh net-edit default
  3. Edit the <ip> element in the configuration file for the default network to include the appropriate address, network mask, DHCP address range, and boot file, where BOOT_FILENAME represents the file name you are using to boot the guest virtual machine.
    <ip address='192.168.122.1' netmask='255.255.255.0'>
       <tftp root='/var/lib/tftp' />
       <dhcp>
          <range start='192.168.122.2' end='192.168.122.254' />
          <bootp file='BOOT_FILENAME' />
       </dhcp>
    </ip>
  4. Boot the guest using PXE (refer to Section 15.2, “Booting a Guest Using PXE”).