What should you be thinking about Virtual Server? There are four areas to consider when evaluation Microsoft's virtualization solution for your infrastructure. Let's take a look.
Hardware support
Beta 2 of Service Pack 1 rounds out the new support for the virtualization technologies shipping on today's server-oriented processors. The Intel Virtualization Technology is chip-based instruction support for software on the host system to run multiple operating systems and applications in independent partitions, each getting an equally deep slice of the CPU pie. It effectively takes the whole of the system's processor or processors and divides them among all virtual machines running on a host. This native hardware support for virtualization performs significantly better than pure emulated, software-only virtual machines. (It's essentially the same concept as the old Virtual 8086 mode, whereby you create DOS-based virtual machines in parallel.)
AMD has a similar set of instructions for its newer processors, a technology code-named Pacifica, that accomplishes much the same result. Virtual Server takes advantage of these new sets of instructions to improve the performance, reliability and resource usage of large nuMBers of virtual machines running in tandem across one host. Of course, you can turn support for these instructions on and off on a per-VM basis using the administrative interface.
Volume Shadow Services