I am looking into virtualizing desktops for a large office, and I haven't been able to figure out how I would accomplish access to a VM instance per user.
We are considering using sunrays as our point of access, from which I assume we would launch a VNC connection into a VM. At this point I'm at a bit of a loss -- how would I ensure that we either launch a VM if it is not already running, or connect to their existing VM if it is already running? Or would the solution here be to make sure that all possible instances are already running, but 'paused' until someone tries to connect to them?
We are are still considering our options in terms of virtualization -- Hyper-V, KVM, Xen, or other.. on one hand we're enthusiastic about open-source products so KVM and Xen are attractive choices, but on the other hand we want administrator training to be as painless as possible so products like Hyper-V have their allure too.
I know this is a fairly sprawling topic I've put up, but I'd appreciate any advice anybody has to offer on the topic.