Note: Almost all content here will eventually be revised and merged into the live-manual. Please do not add new content to the wiki, but contribute to the manual directly.

Here's a quick (and growing) guide for creating live Xen images using debian live.

Intro

Xen is a virtual machine monitor (hypervisor). It offers some neat features - check out http://wiki.xensource.com/xenwiki/XenIntro for a thorough intro.

The virtual machine host portion is called "Dom0", which can be Debian with a xen kernel. DomU is the guest operating system. It can also be a regular debian live image (iso for example).

Dom0 Config

For Dom0 creation, you can use lh_config from live-helper: 

$ lh_config --linux-flavours "xen-686"
$ lh_config --linux-packages "xen-linux-system-2.6.18-4 squashfs-modules-2.6.18-4"
$ lh_config --packages "xen-ioemu-3.0.3-1"

Unionfs

There is still no official Debian unionfs module for Xen kernels (if there is, please update!), so we need to build it manually: 

m-a -k /usr/src/linux-headers-2.6.18-4-xen-686 -l 2.6.18-4-xen-686 build unionfs

To make live-helper use this, the resulting .deb in /usr/src should be copied into config/chroot_localpackages directory.

Xen configuration

If you have an HVM (Hardware Virtual Machine) compatible computer, you can use the configuration:

guest.conf: 

device_model = '/usr/lib/xen-3.0.3-1/bin/qemu-dm'
kernel = "/usr/lib/xen-3.0.3-1/boot/hvmloader"
builder='hvm'
memory = 256
name = "guest"
pae=1
disk=['file:/live_media/domains/guest.iso,hdc:cdrom,r']
boot = "d"

<non-HVM config here...>

grub

grub is needed as the bootloader because Xen kernel does not play well with syslinux. 

title LiveXen
kernel /boot/live/xen-3.0.3-1-i386-pae.gz console=vga dom0_mem=256MB
module /boot/live/vmlinuz-2.6.18-4-xen-686 initrd=initrd.img-2.6.18-4-xen-686 max_loop=255 boot=casper
module /boot/live/initrd.img-2.6.18-4-xen-686

dom0_mem=256MB is used mainly for testing reasons.

Putting it all together

The resulting image should contain the following: 

/boot - kernel, initrd, xen
/casper - filesystem.{squashfs,dir,*} (of Dom0)
/domains - guest.conf, guest.iso

Starting guests

After the boot xend service should be running, allowing guest operating systems to run. To start our guest debian live: 

xm create guest.conf