People ask me what I think of Virtualisation and whether I would virtualise SBS or Cougar or 10 desktops or more. If we are talking about OS virtualisation, rather than application virtualisation then many people miss what virtualisation is - the running of more operating systems on one single piece of hardware. This means that before you had, for example, 3 OSs to manage and now you have 4 (the OS running the virtualisation technology / layer and the 3 OSs that you now virtualise). Now you do have to manage less hardware, but a single hardware failure now will stop 4 OSs rather than 1, so you need to plan around this. Obviously virtualisation gives you benefits in portability and resources management as well as potentially increased hardware specs without the same increase in costs, but you also need to be aware of the issues. I see two major issues outside of those people often think about (as above): Not enough resources. The process of virtualising an OS costs some tax in terms of performance of CPUs, disk...