Bryan Clark, Red Hat designer, wrote a new article for IBM about Xen a week ago:
Xen is a virtualization technology available for the Linux™ kernel that lets you enclose and test new upgrades as if running them in the existing environment but without the worries of disturbing the original system. The author shows you how to install Xen using Fedora Core, but once installed, everything works the same in Xen on any distribution. Take a look at virtualization on Linux and see the benefits of having a sandbox for testing new software, as well as a playground for running multiple virtual machines on the same Linux box.
With a steady flow of improvements and bug fixes to existing software, the open source world is in constant flux. Staying at the bleeding edge of software upgrades can be a full-time job. One of the trickiest parts about upgrading your software is that you never really know if your applications are going to work after the upgrade is complete. Most software packaging systems offer a rollback feature, but that’s often not enough; ideally, you want to play with these new updates to test and try them in an environment where they can’t hurt anything.
Like a kid on the playground, you want your own sandbox to play in, where you can make a mess and not worry about picking up.
Read the whole article here.