Xen is a powerful new virtualization system that enables you to run multiple operating systems on one computer. Here's how you can install it on your Fedora machine, and how to get it configured to best suit your environment.

Virtualization versus paravirtualization

When you create a new VM, it is allocated a chunk of RAM all to itself, and lives completely self-contained from the outside world. VMware even has a virtual BIOS to complete the illusion. If your VM wants to communicate to other VMs on the same computer, it has to do so over a TCP/IP network connection, just like any other machine. In fact, when you install an operating system on a virtual machine, it cannot even tell that it is a virtual machine because it looks identical to raw hardware.

The problem with this type of virtualization is that it is very slow. The solution is to move from virtualization to paravirtualization -- the technique that Xen uses.

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