Microsoft Corp. last week fleshed out the details of a plan to build virtualization capabilities directly into Windows as part of its effort to catch up to virtualization software market leader VMware Inc.
Microsoft plans to adopt an architecture similar to the one VMware uses—a point that VMware seized upon as a validation of its technical direction. But Microsoft said vendors won't be able to differentiate themselves on virtualization alone once the technology is supported in operating systems and chips.
The virtualization road map that Microsoft laid out at its Windows Hardware Engineering Conference here includes a lightweight "hypervisor" layer of code that will be built into the next major version of Windows, code-named Longhorn, to support the creation of virtual machines.
Microsoft is even "leaning" toward eliminating future versions of its Virtual Server and Virtual PC products, said Mark Kieffer, group program manager of Windows virtualization. But Kieffer added that a decision hasn't been finalized.
More immediately, Microsoft plans to work with unidentified industry partners to expand the support of third-party guest operating systems, including versions of Linux, in the first service pack update for Virtual Server 2005. The update is due by year's end and will also include 64-bit compatibility and improved performance, Microsoft said.
The plans weren't enough to sway Jason Agee, a lead infrastructure systems analyst at the Nebraska Health and Human Services System, from his commitment to VMware.
"Too little, too late," Agee said, adding that VMware's more mature virtualization software performs better on less-powerful hardware and is helping the agency to improve its server utilization rates.
But Tom Bittman, an analyst at Gartner Inc., said that the integration of virtualization technology with operating systems should spur broader adoption. Novell Inc. and Red Hat Inc. also plan to support virtualization technology in their Linux distributions.
Microsoft bought its way into the virtualization market two years ago through its acquisition of Connectix Corp., and it released Virtual Server 2005 last fall. Analysts said Microsoft entered the market primarily to give users of older Windows versions an upgrade path to new hardware.
But consolidating Windows NT servers with Virtual Server requires users to run a copy of Windows Server 2003 as the host operating system. The performance overhead inherent in that approach will be reduced when Microsoft moves to its hypervisor architecture, said Ben Werther, a senior product manager for Windows Server.
In contrast, VMware's rival ESX Server, first released in 2001, doesn't require a host operating system. Instead, it uses a hypervisor layer that runs directly on the hardware.
At WinHEC, Microsoft officials showed diagrams with the planned Windows hypervisor code layer, which will divide a system's resources among different virtual machines. Longhorn users will be able to configure the operating system for a virtualization "role," stripping out unneeded functionality in a so-called MinWin configuration, said Werther. But, he added, it's still not clear if the hypervisor technology will make the firstrelease of Longhorn Server that's due in 2007.
Performance also is expected to improve as a result of the hypervisor's support for upcoming virtualization extensions in chips from Intel Corp. and Advanced Micro Devices Inc.
Steven McDowell, a division marketing manager at AMD, said CPU overhead currently runs at 10% to 30% on virtualized servers. But, he added, AMD hopes the overhead will be "negligible" with its Pacifica virtualization technology, for which AMD released a specification last week.
Bob Armstrong, director of technical services at Delaware North Cos., said the Buffalo, N.Y.-based hospitality services provider is happy with the software it bought last year from VMware, which is a subsidiary of EMC Corp. Armstrong said Microsoft is heading in the right direction by building virtualization technology into its operating system, but he fears that "it's going to take them a long time."
Frank Gillett, an analyst at Forrester Research Inc., said it will take at least two years for Microsoft to deliver on its Longhorn virtualization plans. In the meantime, he added, VMware must figure out how to stay ahead of Microsoft and Linux vendors, with general-purpose management software as one option.
Raghu Raghuram, senior director of strategy and market development at VMware, said Microsoft is acknowledging that "if you want to get into the data center, you need to run an architecture that runs like ESX Server."
But, Werther said, "the real challenge will be managing hundreds or thousands of virtual machines across a data center." Microsoft has significantly increased its investment in virtualization management across its System Center family of management tools, he added.