As a guy who's getting more and more involved with VM's in the environment, with more of them becoming mission critical, this is exactly the kind of insight I'm keen on seeing.

I had alreday come to the same conclusions about a couple of the aspects of machine virtualisation, specifically Highest performance and what's being referred to here as Full separation. I can't see the point in trying to virtualise an application that, sitting on it's own, will max out DAS data pipelines, or consume huge amounts of processing power on a regular basis. I also like have infrastructure like firewalls to be completely separated from the vagaries of virtualisation technologies. If I've got a network related issue that's likely to be firewall related, I don't want to have to start figuring out if it's the virtual switching that's got it's knickers in a twist, before I start looking at the firewall proper.

I like the comment from Jim Wilson with regards the requirement for user-level interaction with a particular machine too. I hadn't thought about the need for staff to simply reboot the machine when I'm not here, but it makes perfect sense to be aware of that. Thanks Jim. Having thought of that though, I would extend that premiss for any machine that requires access on a regular basis by not-so-technical contractors or maintenance staff too. I don't want these people to have access to VM level infrastructure management, nor do they need the excuse that it's the VM infrastructure at fault, not their software/systems.