PUBLIC MARKS from camel with tags build & xen

The idea of using virtual machines to build high available clusters is not new. Some software companies claim that virtualization is the answer to your HA problems, off course that's not true. Yes, you can reduce downtime by migrating virtual machines to another physical machine for maintenance purposes or when you think hardware is about to fail, but if an application crashes you still need to make sure another application instance takes over the service. And by the time your hardware fails, it's usually already too late to initiate the migration.

This guide is the first of a series in which I give you detailed step-by-step instructions on how to build a virtual cluster with Xen. The cluster thus built might not be appropriate for your case, and does reflect the author's preferences and/or needs, but if you are new to clusters or Xen, it will hopefully help you get started with both. The goal is to start it simple and then add more complexity as we progress, so in this first guide I show you how to get do the basics: * A Xen installation, the creation of 5 virtual machines (one to act as the master and four slaves), * Shared storage through NFS, * The network configuration on which to build the virtual cluster. The network structure of this first attempt will be very simple, the master having two network cards, one to the outside world and the other one connected through a switch to the slaves.