In-Depth

Microsoft Makes Peace with Virtualization

Earlier this month Microsoft committed to a very sudden about-face on its virtualization strategy

With all the news about IBM Corp. buying Cognos for $5 billion, you might have missed news from Microsoft Corp.. The software giant has committed to a very sudden (and inescapably public) about-face on its virtualization strategy.

Since its first foray into virtualization (Microsoft Virtual Server), Microsoft has tried to tackle the technology on its own terms. Even though VMWare, Virtual Iron, Citrix, and other competitors sell hypervisors that function independently of any specific operating environment, Microsoft wanted to market an operating system (Windows Server) that is the hypervisor (see http://esj.com/enterprise/article.aspx?EditorialsID=2823).

That was its traditional stand. Just recently, however, Redmond shifted gears, announcing a new standalone hypervisor -- its Hyper-V Server (derived from Hyper-V, the official brand for the former Viridian technology) -- that lets customers virtualize heterogeneous workloads onto a single server. In this respect, Hyper-V doesn’t sound all that different from VMWare’s ESX Server or, for that matter, any of a dozen other prominent hypervisors.

Don’t be too quick to dismiss or downplay the significance of Microsoft’s about-face. Industry veteran Gordon Haff, a senior IT advisor with consultancy Illuminata, says it’s a Very Big Deal.

"Microsoft’s decision to offer a hypervisor that’s not part of the operating system [is] striking, given that they have been the most vocal proponents of the ’virtualization-as-a-feature-of-the-OS’ point of view," Haff points out.

After all, Microsoft’s mantra is also conveniently self-serving: it lets Redmond sustain its lucrative Windows licensing paradigm -- which emphasizes the importance of a Windows client on every desktop and of multiple Windows servers in every backroom -- even as it accommodates (on Microsoft’s terms) the virtualization juggernaut. In Microsoft’s scheme -- or in its scheme until last week -- the operating system (namely, Windows) trumps the hypervisor because the operating system is the hypervisor.

"[I]n fact, there’s a long history of operating systems subsuming functions and capabilities that were once commonly purchased as separate products. Think file systems, networking stacks, and thread libraries," Haff explains.

What caused Microsoft’s about-face? It’s simple, Haff argues: sometimes the world -- sometimes even Steve Ballmer’s world -- doesn’t work the way MS would like it to.

"Separate hypervisors are a better match for the sort of heterogeneous environments typically found in enterprises than are those built into OSs," he points out. "There’s also a major trend afoot to embed hypervisors into x86 servers, just as they are already embedded into Big Iron. Among the early system vendors to announce or preview intentions in this area were Dell, HP, and IBM. Embedded hypervisors pretty much trump any integration advantage that virtualization-in-the-OS enjoys. You can’t get much more built-in than firing virtualization up when you turn the server on for the first time."

The upshot, Haff observes, is that not even a behemoth like Microsoft can afford to buck a prevailing market trend -- even if it means risking, however slightly, its established Windows licensing model.

"I expect that this style [i.e., the use of a standalone hypervisor] of delivering the foundation of server virtualization is going to become commonplace," he asserts. "It will be a while before who wrote a particular hypervisor becomes a genuine ‘don’t care’ to most users -- the way BIOSs are today," he concludes.

"Standards for managing and controlling virtual machines are still nascent and the whole area is far too new for true commoditization, but it’s the direction things are headed. Even Microsoft, however reluctantly, has now accepted this even while it simultaneously tries to … keep as much … control as possible."

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