The basic components of a Xen-based virtualization environment are the Xen hypervisor, the host desktop environment, any number of other Xen-based virtual machines, and the tools, commands, and configuration files that let you manage virtualization. Collectively, the physical computer running all these components is referred to as a virtual machine host because together these components form a platform for hosting virtual machines.
The Xen hypervisor, sometimes referred to generically as a virtual machine monitor, is an open-source software program that coordinates the low-level interaction between virtual machines and physical hardware.
The virtual machine host’s desktop environment, also referred to as domain 0, is comprised of several components, such as:
The SUSE Linux operating system, which gives the administrator a graphical desktop and command line environment to manage the virtual machine host components and its virtual machines.
host desktop is used to refer to the domain 0 management environment, even though the SUSE Linux operating system might be running in command line interface mode with no graphical desktop.
The xend daemon (xend), which stores configuration information about each virtual machine and controls how virtual machines are created and managed.
A modified version of QEMU, which is an open-source software program that emulates a full computer system, including a processor and various peripherals. It provides the ability to host operating systems in full virtualization mode.
A Xen-based virtual machine, also referred to as a domain, consists of the following components:
At least one virtual disk that contains a bootable operating system. The virtual disk can be based on a file, partition, volume, or other type of block device.
Virtual machine configuration information, which can be modified by exporting a text-based configuration file from xend or through Virtual Machine Manager.
There are a combination of GUI tools, commands, and configuration files to help you manage and customize your virtualization environment.