"Microsoft has a long way to go [in virtualization], kind of like their mobile phones," Gray says. "It will have to be extensive, groundbreaking stuff in order to really steal that market share."
Raci Dearmas, lead engineer at Overlake Hospital in Bellevue, Wash., also tested Hyper-V and says "It was a lot more complex to manage. Not only that, but having a team that is already familiar with VMware, to go to something totally different and manage two separate systems wasn't ideal for us."
Configuration of virtual LANs is one area in which Dearmas says Hyper-V was problematic.
"It's just a less mature product," says his colleague, Joseph Wolfgram, director of IT at Overlake.
Another VMware customer, systems administrator Jason Morris of Fermilab outside of Chicago, says he hasn't tried Hyper-V yet but that the high price of VMware is making Microsoft look like a decent option. The recent addition of live migration into Hyper-V makes the product more viable, he says.
"The cost of VMware is definitely making [Hyper-V] look a little more interesting to me," Morris says. "It's something that I'm definitely interested in looking into.”
Microsoft is trying to argue that Hyper-V can be adopted by even the largest enterprise customers, noting that Fortune 500 company CH2M Hill is phasing out VMware in favor of Microsoft. But even in that case, CH2M Hill says it will take three to five years to get rid of VMware, in part because of existing software licenses and maintenance contracts.
Microsoft virtualization chief Mike Neil boasts that Hyper-V market share is growing faster than VMware's. "I feel pretty confident that we’re on the right track," he says. "Obviously, we've got customers deploying it in enterprise environments."
VMware CEO Paul Maritz tried to throw cold water on the market share argument, though, claiming that VMware is still the clear leader when it comes to large virtualization deployments. He suggested that Microsoft's rise in market share is due to a large number of people using Hyper-V for small projects.
"By any measure, in terms of serious usage of hypervisors in businesses we are far and away the company with the largest market share," Maritz said in a Q&A session with reporters. "Now, that being said clearly Microsoft is a company with enormous resources."
VMworld in San Francisco is VMware's customer event, so it's not surprising that attendees are wary of switching to Microsoft's Hyper-V. But nearly every company in the Fortune 1000 uses VMware, and all of the companies in the Fortune 100 are VMware customers. Microsoft would be hard-pressed to convince a majority of those customers to switch, but it's definitely on the table for smaller companies that are just getting started in virtualization.
"Typically, when we see demand for Hyper-V from customers it's usually for a monetary purpose," and in cases when the customer is starting a new virtualization deployment, says Anoj Willy, a solutions architect for INX, a reseller that partners with both Microsoft and VMware.
Bennett says if he were starting a brand-new virtualization project he'd examine VMware, Microsoft, and Citrix's XenServer, but probably still choose VMware for production applications.