Microsoft last week completed development of its System Center Virtual Machine Manager, a mouthful of a name for a product that's actually quite interesting. Virtual Machine Manager also may be a bit confusing, especially if you've been using Microsoft's Virtual Server platform or are charting a migration to the company's hypervisor-based Windows Server Virtualization technologies when they're released shortly after Windows Server 2008 launches early next year. Here's a quick primer on these technologies:
Today, Microsoft offers a free product called Virtual Server that provides a traditional (i.e. user mode) virtualization environment. Virtual Server could very well be the pinnacle of this type of technology, at least from Microsoft, given that it will be obsolete as soon as the better performing, more maintainable, and more efficient Windows Server Virtualization arrives next year. For those looking ahead to this future, Virtual Server's VHD-based virtual machines (VMs) will work fine--if not quite a bit better--if and when you later upgrade to Windows 2008 with Windows Server Virtualization.
On the management side, Virtual Machine Manager is an enterprise-class VM management solution that's currently aimed at Virtual Server customers but will presumably be updated for Windows Server Virtualization once that technology becomes available. It extends the basic capabilities of Virtual Server management, which is generally designed for managing the VMs on a single physical server, into a more scalable solution. Virtual Machine Manager offers centralized VM management across hundreds or thousands of physical machines and can handle thousands, or even hundreds of thousands, of VMs.
Virtual Machine Manager automates many crucial tasks. For example, VMs that are running out of resources on one physical machine can be automatically relocated to new hardware with minimal disruption and end user transparency. It also provides for physical-to-virtual conversions, as well as virtual-to-virtual conversions of VMware VMs to Microsoft VMs. (And say what you will, but that last feature should prove quite popular.)
Unlike Virtual Server (and the upcoming Windows Server Virtualization), Virtual Machine Manager is not free, but given its expansive feature set this is not surprising. You can get into Virtual Machine Manager as cheaply as $499 for a version that can manage up to five physical host servers. Beyond that, you're in volume-licensing territory.
Windows Server Virtualization, an optional component, or role, in Windows 2008, is less understood at this time. I've seen rumors online that Microsoft is prepping a release candidate version of Windows 2008 in the coming weeks that will include the first public pre-release version of Windows Server Virtualization. Although I can't speculate on these rumors or confirm them, I'm hoping we'll soon be able to have a much more detailed conversation about what Microsoft is doing with virtualization and how its virtualization management tools will be evolving to address those changes. Right now, we know that Microsoft plans to ship Windows Server Virtualization within 180 days after Windows 2008 releases to manufacturing (RTMs), and that Microsoft will ship a public beta of it at Windows 2008 RTM.
Windows Server Virtualization is hypervisor-based and uses a more efficient, non-emulated device driver layer, which should result in better performance than today's Virtual Server-based VMs. And although the Windows Server Virtualization platform runs only on Windows 2008--and just the x64 versions--I don't expect that will cause much of an uproar with mainstream enterprise customers, especially if Microsoft is able to get 32-bit and 64-bit Linux VMs running efficiently under the system. Besides, businesses will be able to install Windows Server Virtualization in Windows 2008's efficient and secure Server Core environment, which should provide most of the benefits of Linux on the server without the management headaches.