VMware still reigns supreme for veteran virtualization users, who say Hyper-V is far from being a strong option in heterogeneous data centers and question XenServer's long-term viability.
Meanwhile, Oracle and IBM may shake up the top three virtualization vendors.
At Citrix Systems Inc. Synergy 2009 conference this month, IT managers and partners said they see increasing interest in Citrix XenServer, which has only about 2% of the virtualization market today, according to 2008 numbers from Gartner. VMware has 89% of the market, and Microsoft has 7% with Hyper-V, according to Gartner Inc.
But many current VM users don't see XenServer as a long-term player and remain loyal to VMware despite the high cost.
"I'm betting Microsoft is seven to 10 years from being the player they want to be," said Kevin Donnelly, a former CIO and the principal of Laurel, Md.-based Kaditcha Consulting, which offers IT consulting to CIOs and CTOs. And I think the Citrix XenServer solution will hold [its current] position until the slow demise of fat applications drains Citrix's pockets and they have to lead with XenServer rather than the other way around. I'm not sure there is money [in XenServer] to keep it in the race for the long haul."In it for the long haul: The hypervisor debate
Debates about which virtualization offerings will survive long term also rage on IT community websites like Ars OpenForum, where many IT pros concur that Hyper-V has a lot of growing up to do and XenServer's days are numbered.
"Hyper-V would be nice if their integration components worked on stuff besides [Novell] SUSE. Red Hat [support] is coming, but what about free distros [i.e., distributions] like CentOS and Ubuntu?" one virtualization user wrote in response to a question posed about VMware, Hyper-V and XenServer preferences. "My perception is XenServer doesn't have a long future. It seems, like with everything else, there is a No. 1, a No. 2, and everybody else."
Another user wrote that Citrix' recent efforts to update XenServer are futile. "Citrix is putting a lot of resources into development. The next release adds Distributed Resource Scheduler (DRS), for instance, among other features. [But] they won't catch vSphere [because they have] no storage vMotion, no distributed switch, etc., etc.," he said. "But, they are much farther along with features than Microsoft at the moment."Other IT pros consider Citrix a solid option, and its free features, such as live migration, add appeal in a tough economy. One systems engineer from a U.K. education organization on the Ars OpenForum that he chose XenServer because it offers more bang for the buck. "We and a lot of the other organizations we talk to are basing virtualization projects on Citrix because we get a lot more before we have to start paying compared to VMware," he said. "The money we save can be ploughed back into hardware or other areas where funding is deficient." Vendor preferences: A religious experience
For some IBM and Linux fanatics, virtualization preferences are almost a religious matter, Donnelly said.
"You have the pro-Microsoft camps and the anyone-but-the-evil-empire-ists on the other side. Then there's the open source Xen versus the gotta-have-a money-making support team behind it' camps," Donnelly said.
That is the mentality of one network administrator with a major insurance company in Warwick, RI who is just starting to virtualize. She refuses to go with Hyper-V because "Microsoft is already everywhere." Plus, VMware is a better known, well regarded technology in the virtualization space with the best features available, she said.
VMware also has a stranglehold on the virtualization market because it got there first, and enterprises that have invested heavily in its technology don't want to switch.
"Most of the folks I talk to are not willing to adopt Microsoft yet, and it may be that Microsoft got into the virtualization game too late," Donnelly said. "It will be a many year struggle for them to get the market share in the commercial space that they want, much like the years it's taken for SQL Server to be considered ready for prime-time by major enterprises, because Microsoft got in so late, but they are tireless and do look long term at technology spaces that they see as a threat to the OS gravy train."VMware support wins kudos
While VMware enjoys a good head start, the company wouldn't be at the top of the market if its features and support hadn't gained customer loyalty. Karl Barnes, a senior network administrator with the city of Alexandria, Virginia, for instance, began virtualizing three years ago and chose VMware when it was one of the only solid options, but wouldn't consider defecting because the software and support have been second to none, he said.
"VMware offers the best support of anyone, hands-down. They have been able to diagnose any issue I've had in less than five minutes, every time," Barnes said. "Microsoft's support is good too, if you can get through to them."
Plus, VMware's product has had time to prove reliability to users. Barnes runs three ESX clusters and has yet to experience an ESX "break." "Systems break because of OSes, not hypervisors, so I don't like the idea of running OS virtualization," he said.Watch for VM wild cards
While the top three vendors share the limelight, a few wild cards could give them trouble. One is Oracle, which just purchased Virtual Iron Software to enhance its Oracle VM virtualization offering, showing virtualization users that Oracle doesn't want to play second fiddle in this market forever.
"They had, until recently, been a dark horse, low-cost cult favorite, but that's all changed now. … The Virtual Iron purchase will immediately boost them into serious player status," Donnelly said. "Oracle is a real wild card, and it's too early to tell what impact they will have, other than to be fairly sure there will be an impact."
"Another very dark stealth horse" is IBM PowerVM, Donnelly said. "They are planning to virtualize Microsoft [applications] on a System Z, just like they do with Linux IFL and that may really shake some things up if it is real and does work, since they are still major players in the very large enterprise space and their stuff is well regarded in terms of the it-never-goes-down set," Donnelly said.Still, IBM, Oracle and Virtual Iron have miniscule share of the virtualization market today, and VMware will probably continue to dominate for another decade, analysts and users predicted.
"VMware will continue to lead the market for at least the next five to seven years, unless someone makes some significant technology breakthrough. There are lots of deep pockets playing in this now - so it's a crap shoot in my book," Donnelly said.
"VMware is the 800 pound Gorilla in this space and they have EMC money behind them, but XenServer has Citrix behind them, and they offer a potentially wider solution when the server and desktop are considered, since Citrix is still the bigger player in the desktop side," Donnelly said. "That only leaves that small player Microsoft, who, as in most technologies is far from the bleeding edge, but always a threat."