How to: Install and Setup XEN Virtualization Software on CentOS Linux 5

http://www.linuxtopia.org/online_books/centos5/centos_5_xen_virtualization/centos5_chap-Virtualization-Compatibility_of_host_and_guest_combinations.html
http://www.howtoforge.com/paravirtualization-with-xen-on-centos-5.3-x86_64