Virtual Server 2005 Frequently Asked QuestionsQUOTE
Q. What is virtual machine technology?
A. Virtual machine technology applies to both server and client hardware. Virtual machine technology enables multiple operating systems to run concurrently on a single machine. In particular, Microsoft Virtual PC products enable one or more operating systems to run on the same computer system as the current Windows operating system. Today, many x86-based operating systems are supported by Virtual PC 2004 and Virtual Server 2005. In addition, Virtual PC for Mac enables one or more other operating systems to run on the Macintosh operating system so that users can run a Windows operating system and Windows applications on a Macintosh.
Q. What is virtual machine technology used for?
A. Virtual machine technology serves a variety of purposes. It enables hardware consolidation, because multiple operating systems can run on one computer. Key applications for virtual machine technology include cross-platform integration as well as the following:
• Server consolidation. If several servers run applications that consume only a fraction of the available resources, virtual machine technology can be used to enable them to run side by side on a single server, even if they require different versions of the operating system or middleware.
• Consolidation for development and testing environments. Each virtual machine acts as a separate environment, which reduces risk and enables developers to quickly recreate different operating system configurations or compare versions of applications designed for different operating systems. In addition, a developer can test early development versions of an application in a virtual machine without fear of destabilizing the system for other users.
• Legacy application re-hosting. Legacy operating systems and applications can run on new hardware along with more recent operating systems and applications.
• Software demonstrations. With virtual machine technology, users can quickly recreate a clean operating system environment or system configuration.
• Simplify disaster and recovery. Virtual machine technology can be used as part of a disaster and recovery plan that requires application portability and flexibility across hardware platforms.
This, of course, applies only to the Microsoft Virtual PC/Server technology. Basically, a physical server can run any number of virtual servers, within it's resource (CPU/RAM/etc) limits. Intel, AMD, Microsoft, and others are trying to push it for everyday usage, but I think it still has a long way to go for that. Sure, the server hardware is definitely powerful enough to run multiple virtual servers in certain instances, but you're putting everything down to one point of failure. Admittedly though, a virtual server is much easier to recover since all you have to do is restore the virtual hard drive files on another physicaly server and you're back in business.
Peronally, I'm only confident enough in it at this point for testing and development environments. Give it another few years and it'll definitely be to a point where it can be used for live business applications.