A Primer On Microsoft's New Hyper-V

Don't Step On Any Toes
Hyper-V comes as an integrated service in Windows Server 2008, so it is not a hosted platform. The integration gives Microsoft a huge advantage over VMware because customers can get two products for the price of one. A fight for data center supremacy might emerge out of this technology. Windows and Linux are no longer on equal footing due to Hyper-V's low-level control over kernels and competing hypervisors.

However, few versions of Windows Server 2008 Standard and Enterprise do not require Hyper-V, so Microsoft must tread carefully to not impede other hypervisors and open source OSes from competing with its virtualization technology and new server OS, respectively.

From Hyper-V's standpoint, Windows and Linux guest OSes are able to control hardware devices on their own. For instance, Hyper-Vs can receive instructions from guest OSes to perform hardware reboots. In addition to power states, other hardware properties, including resources, are available programmatically.

Microsoft is following its Open Specification Promise—a covenant with the industry to provide documentation on how some of its technology works. As such, it has provided a document detailing all the interfaces and CPU register accesses available in Hyper-V. The document allows developers to develop compatible hypervisors. The information provided is high level, however, and does not follow standard documentation format.

In addition to the hypervisor, Microsoft is providing a list of its enterprise middleware that can be tested in Hyper-V. Products such as BizTalk Server 2006, Exchange Server 2007 SP1, Office Sharepoint Server 2007 and many others conform to Hyper-V's virtual hard disk (VHD) format and are available as preconfigured VHD packages. Partners like Citrix Systems, Quest Software and SplendidCRM are providing package solutions using the VHD format. For now, Microsoft is staying with the VHD file format that was available back in 2005 with Virtual PC 2004.

But there's more to virtualization than hypervisor technology. Managing virtual domains in large data centers requires sophisticated tools. VMware, based in Palo Alto, Calif., offers a wealth of enterprise management tools and so does its partner community. XenSource, also in Palo Alto, recently shifted its product line to better align itself with large data centers. Other than VMware and XenSource, other hosted virtualization platforms will probably not be able to compete head on with Windows Server 2008.

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