Summary

Prerequisites

• You have to download the DVD iso image. CD images may work too, but untested.
• You need a nfsserver. The dom0 (the Suse 10.2) machine can do that. The examples assume that this is so. If you choose to put the files somewhere else you might change the paths somewhere.
• Recommended: a working dhcp server
• A pae kernel with xen running. Install the "xenpae" Kernel and boot this kernel. If you do not so, you'll get a not very verbose error message when starting domU virtual machines: "error 22 invalid argument".

Environment

Mount your iso image and copy it to a directory that can then be nfs exported:

mount -o ro,loop CentOS-5.0-i386-bin-DVD.iso /mnt
mkdir -p /export/CentOS-5.0-i386
cp -a /mnt/* /export/CentOS-5.0-i386

put in /etc/exports:

/export/CentOS-5.0-i386 *(ro)

and use exportfs -a to export it via nfs.

Start domU install

Use yast2 and go to System, then "Virtual Machine Management (Xen)". Create a new virtual machine and choose "Operating System Installation". Here choose "ISO Image File" and point to the iso file. For some unknown reason the iso file has to be writable to root. If not you'll get the error message "Device 832 (vbd) could not be connected. Backend device not found". You may ask: "Why a iso here, when i have copied the iso?". Answer: For some reason the centos installer does not see or mount that.
Choose "Other Installation Source"
In the field "kernel" put the path to the copied iso and within to the file "images/xen/vmlinuz".
In the field "initrd" point to "images/xen/initrd.img".

Installer

Pushing "next" should start the VM in a new xterm. Within the text-installer choose "NFS image", setup your network (do not choose IPv6, it seems to slowdown installer) and setup your nfs server information (name or ip and /export/CentOS-5.0-i386 as Directory).
The installer should start a vnc server and you can connect to it with vncviewer. Unfortunately it only worked once for me. I'm investigating why ...