Virtualization: Xen Installation

How Xen works?
Xen hypervisor is run on top of the hardware which is the virtual machine monitor. Guest operating systems are run on top of this hypervisor, thus all guest operating systems are secondary to the hardware and contacts the hardware through the hypervisor. The first thing for grub would be to load the hypervisor. Look at the /boot/grub/grub.conf which loads the xen.gz-2.6.18-128.4.1.el5 which is the hypervisor.

Hypervisor loads the Dom-0 kernel and initrd image and starts the main system. Dom-0 itself is a guest operating system with additional privileges to manage other guest operating systems and is started with system start up.

Following rpms should be installed for Xen virtualization,
- kernel-xen ---> Dom-0 and Dom-U kernels.
- xen ----------> Xen hypervisor and other management tools.
- libvirt ------> Libraries required to manage domains which is used as a backend for virtmanager. http://libvirt.org
- virt-manager ----> GUI interface to manage guests

Once installation of above RPM's are done, System should be rebooted using the new XEN kernel.