Note: I lost my original xen config files so I've created new ones here. I no longer have a xen system so I can't test them. Please let me know if the tutorial still works or not - Grant
A lot of this tutorial was stolen from my CentOS 5 Installation which in turn was stolen from the CentOS wiki. I've shortened and updated it for installing a CentOS 6 DomU. I just copy and paste all the indented lines into a root terminal and voila! a CentOS VM.
1. Creating an Virtual Disk Image
The first step is to create an disk image that will act as the VM hard drive. The following command will create a 4 GB sparse disk image named /srv/xen/centos6.img. A sparse file is created in such a way that the disk image doesn't actually take up the whole 4GB until you fill it up. If you'd like a larger (11GB) disk image substitute seek=10240 into the following line. I make my VMs nice and small so I can move them around easier. Making a disk image larger or adding a second drive later is easier than making it smaller or taking a drive away.
dd if=/dev/zero of=/srv/xen/centos6.img oflag=direct bs=1M seek=3800 count=1
2. Preparing the Xen configuration file for installation
Xen uses one configuration file per VM. We will start out with a config to do the install and replace it later with a config for normal operation. Now we download the install kernel, ramdisk and xen config file.
wget http://mirror.centos.org/centos/6/os/i386/isolinux/vmlinuz -O /boot/vmlinuz-xen6-install
wget http://mirror.centos.org/centos/6/os/i386/isolinux/initrd.img -O /boot/initrd-xen6-install
wget http://www.grantmcwilliams.com/files/xen-centos6-i386-install -O /etc/xen/centos6
3. Starting the installation
A kickstart file holds instructions for automatic installation and is referenced in my xen config above. My example kickstart file is very minimal but is enough to get a working CentOS 6 VM.