"3. Virtual Iron - Based on Xen's virtualization
technology, Virtual Iron is an up-and-comer in this space. Though I
haven't tried their product(s) directly, I hear very good things
about them from other virtualization professionals. I'm not
qualified to say whether or not they offer anything above what Xen
alone offers--that would take some investigation. Perhaps some of
you who've tried Virtual Iron can use the comments section to
inform me of your experiences.
"4. OpenVZ - OpenVZ, Virtuozzo, and Parallels all sprang from
the same origin: SWSoft, which is now Parallels, Inc. These
products are all based on operating system-level virtualization or
containers. Containers are actually a type of BSD Jail or chroot
jail. This is a very efficient and secure type of virtualization
where each virtual machine is really just an extension of the
existing system. It's a bit hard to explain in such a small space
but compared to other types of virtualization, the costs are nil,
the performance is native, and the number of virtual machines can
reach into the hundreds. The only limitation is that you have to
run the same operating system and kernel for all virtual
machines."
