But for some open source advocates, VMware's offer didn't go far enough.
Well-known blogger Jason Perlow said that, without additional software, 3i can cluster only a single box. And without the features that come with the pricy VMware Infrastructure; 3i is merely on par with Microsoft's Hyper-V. And that's not enough, he warned.
"Hyper-V is always going to be a part of Windows Server releases going forward and will be constantly improving, so VMware still has an uphill battle going forward," Perlow said.
The solution, Perlow said, is for VMware to give away not just its basic server but also its source code. In doing so, VMware's ecosystem of developers and integrators will grow, enabling the company "to combat the looming monster that is Microsoft, which will offer its own Type 1 [i.e., a bare-metal or native] hypervisor for free," he said.
Despite relinquishing ownership of their source code, VMware and other providers can succeed, because customers still want supported products, Perlow said. For example, Raleigh, N.C.-based Red Hat Inc. released the code for Red Hat Enterprise Linux (RHEL), which Oracle used to create its competing product Oracle Enterprise Linux with sales that are so marginal that it "hardly amounted to a big win for Oracle," he said. Unless VMware lowers its price and catches up with rivals in adapting to performance-boosting chip advances for Windows Server guests, VMware will be limited to niche high-end markets, he warned.
Benny Schnaider, the CEO of 3-year-old Israel-based startup Qumranet Inc., said that it would be great if VMware Inc. donated its hypervisor code to the open source community, as With its Kernel based Virtual Machine (KVM), released two years ago, Qumranet did. But Schanider doesn't think it's likely to happen anytime soon.
"Time will tell if they will release [the code], but I don't see it coming for two or three years," Schnaider said. "As long as VMware is making money selling [its hypervisor] as closed source, it will probably stay that way."
But because virtualization is part of the infrastructure and not an added feature, VMware will have to use virtualization as a building block to develop a broader array of management tools to prosper as a company, Schnaider said.
Analysts Charles King, a principal analyst at Pund-IT Inc.in Hayward, Calif., and Chris Wolf, a senior analyst at Midvale, Utah-based Burton Group, also don't believe that VMware would release its source code anytime soon.
"At this stage, VMware has more to lose than gain by open-sourcing its hypervisor," Wolf said.
"I don't see how opening its source code would benefit VMware," King agreed. "Until Microsoft and Xen folks are in a more competitive position [vis-à-vis VMware], the concept of commoditized virtualization is a pipe dream."
Even if the hypervisor becomes commoditized, the market might well support several successful competitors rather than coalesce around a single vendor, King added.The hypervisor rivalry
Debate is currently under way on the relative merits of Qumranet's KVM versus Xen's hypervisor, with Ubuntu adopting KVM with version 8.04LTS in April and Red Hat Inc. announcing its intent to follow suit in June. KVM is reportedly more lightweight and easier to deploy than Xen but is part of the operating system. Xen's independence from the operating system reportedly has advantages as well, experts say.
Qumranet's Schnaider, who directed the April launch of Solid Ice, the company's KVM-based desktop virtualization product, believes that KVM's incorporation in the kernel will help it optimize future Qumranet products to run better on Linux than an independent hypervisor. (The company has no plans for a server product, Schnaider said.)
With only 20,000 lines of code, KVM is simpler to develop and maintain than the 300,000-line Xen, he added.
"The best judge of the better hypervisor is the Linux community," Schnaider said. "And the momentum is shifting from Xen to KVM," with Red Hat and Ubuntu both announcing adoption of KVM, he said.
Andy Cathrow, Red Hat marketing manager, said KVM represents "the evolution of Linux virtualization." Because KVM is inside the Linux kernel, hypervisor integration and testing is much easier. And all the latest kernel improvements, like security and real time, accrue to virtualization, too, he said.
Red Hat won't move from Xen to KVM in Red Hat Enterprise Linux 5. But in any case, the company will continue to support Xen "at least through 2014" and will guarantee compatibility between the two hypervisors and their associated tools and scripts, he said.
Cathrow cautioned, however, that although Red Hat will continue to develop new features for both platforms, it "might not make sense" to incorporate all the latest enhancements in Xen, he said.
"Xen's been a great solution, but KVM offers more innovation and faster features," Cathrow said. "Technology moves forward, and KVM is the future."
Red Hat's first priority is to achieve third-party certification with Microsoft's Hyper-V to ensure that Hyper-V-virtualized machines are treated as tier-one guests on RHEL, Cathrow said. Microsoft just announced its certification requirements a few weeks ago, and no vendor platform has been certified yet, he said.