Virtualisation is one of todays IT buzzwords. VMware's ESX server solution allows us to create virtual servers on machines that would otherwise be under employed. Bringing together a number of servers to run on a single physical machine means greater resource utilisation. More importantly servers that once had multiple applications running in a single operating system can run in their own virtual server. Problems with different software applications clashing is nolonger a problem. Urgent updates that are required for show stopping bugs in one application need not halt another unconnected part of the business.

Storing the data on virtualised storage allows migration to more cost effective storage solutions, it can also allow storage to grow as it is needed rather than based upon the predicted requirmements. The resultant savings can be seen by looking at the changes in hardware performance and cost. When projects complete and storage is released it can be used for other projects or disaster recovery solutions.

Combing the two solutions may seem like a real win. However performance can get in the way. System testing may help to highlight any problems before the users have a chance to get irate. The upside for vmware is that they have Storage VMotion so that virtual disks can be moved to different locations to overcome IO bottlenecks. Of course if the bottleneck is in the underlying server the best option is to transfer the VM to an alternative Physical server (sounds more like clustering ...better not go there).