We have stepped up our use of Virtual Machines at network level at Timico and recently rolled out a significant number of Xen based platforms. Xen (see Xen.org).  For those that don’t know a Virtual Machine is a virtual server that can run on multiple hardware devices simultaneously but can be seen as a single entity by the network. 

Because the company has been growing the need to scale up easily has become more and more pressing. Over the Christmas break (the Network Operations team is allowed two hours off for Christmas lunch which they take communally in the kitchen at the NOC 🙂 ) a new email platform was rolled out on Xen based hardware. As the burden of mail inevitably grows all Timico will have to do is add new hardware capacity with no need for network downtime or reengineering.

The beauty of Xen is that it takes very little time to add capacity to a server farm and downtime is minimal or non existent. You can therefore move a service from a small machine to a more powerful one with perhaps as little as 60 milliseconds interruption. 

All new servers are rolled out with Xen now at Timico. Whilst Xen is open source  and therefore free Citrix does sell a commercial version. If you have no skills in this space it could be an option but otherwise drop me a line if you want any advice on the subject.