I’ve been looking at virtualisation recently – both for use within my group and for wider use with the company.
We need to be able to handle Windows VMs as well as proper operating systems, so unfortunately things like Open VZ or its commercial cousin Virtuozzo are not an option, which pretty much leaves Xen (both the Linux distribution hosted version and the Xensource packaged version) and VMWare. Live migration of VMs would be useful, although for its overkill for our group requirements (but having it means we can test how things work in a clustered environment with migration, so its down as a really want if not a must have).
The Xensource packaged Xen versions – we’re evaluating Xen Enterprise – are interesting but appear a little early in their development at present, and have poor SAN/storage options and no current live migration support. VMWare is the most flexible, polished and capable – its also by far the most expensive. Xen running under a Linux distribution (intention is to use Centos 5) has yet to be tested.
More work to see what else is good needs to be done here….