Thanks @TheScarfedOne for your size 10 contribution, you are right and have understood the intention of Phil’s post completely. As a software supplier we have to do our best to make recommendations on how to install our software, this is covered to a large degree in the installation documentation available on the appropriate CD, but it could do with improvement around the area I discussed earlier.
Our advice is to ensure that a school wanting to virtualise their environment should make sure they employ an expert as it is not just about setting up an environment, within your structure, but also the maintenance of the environment, what we do know is that SIMS work very well in a well managed virtual environment. I believe we can make our minimum recommended specification document better, there are ideas in tailoring this for different sized schools and for the products they use, but again, this can only be a best guess as every school will have different requirements, you never know, this may go some way to help address issues people may have currently.
FYI - Documentation have just found resource 19548 on Support .net, a White Paper by Jon Wood regarding considerations when virtualising your network environments.