SanSay.Co.Uk

I'm currently employed as a network administrator at a school, looking after bits of computer hardware. This isn't my real area of expertise - I'm a computer programmer, I want all the grotty hardware stuff (and believe me, in schools some of the hardware truly does get pretty grotty...) to be abstracted away so I can get on with the fun programming stuff. And now I've found the perfect solution - server virtualisation. Yay! Hardware administration for software people! Your physical servers all become simple application servers with one function: to provide a platform for virtual servers. You then go about setting up virtual server for whatever you want. The general idea seems to be to set up a seperate server for each function on your network - so a seperate server for DNS, LDAP, gateway, database, etc. The fun part is when you get things set up so you can migrate virtual servers around physical hardware - move, say, your DNS server from one machine to another without any downtime.

The first task is, of course, to pick a virtualisation system to use. After a days investigating, I've decided to have a go at using Xen. It's open source, so it looks like I'll be able to deploy it system-wide at no cost. It's performance is good - I saw one claim that virtualisation processor overhead is around 3%. However, the technique it uses to achive this performance means that it has to run specially modified operating systems - i.e. Open Source ones only. That is, however, unless you have a processor that supports virtualisation in hardware, then you can run (seemingly) Windows XP / Server 2003. We don't happen to have a server with such a processor yet, but eBay has them at around £250 for a motherboard with processor and 4GB of RAM.

Seemingly, to make sure we can use the snazzy live virtual server relocation system, I'll also need to make storage available as iSCISI devices - SCISI over IP, i.e. SCISI over a network. Looks like there's going to be a bit of a learning curve ahead...