Microsoft itself is taking a run at the server virtualization market, having released its server virtualization software, dubbed Hyper-V, in late June. The server virtualization software is part of the Windows Server 2008 license. A standalone version of Hyper-V that will sell for $28 is expected later this year.
Hyper-V also uses a proprietary file system and includes its own proprietary data protection features, as well. The difference is that the file system in Microsoft's case is NTFS, and the data protection feature VSS, two applications that are already integrated and are well understood by storage users and storage vendor partners.
This also means that in its first general release, Hyper-V will already have many of the advanced features it took VMware years to develop, including high-availability clustering and live migration of virtual machines. VSS-integrated snapshot offerings are also on the market from storage vendors, such as EqualLogic, EMC and NetApp. In addition, every major storage vendor has also already announced support for the Windows 2008 operating system of which Hyper-V will be a part.
"You have to determine early on how to approach virtual machines in your environment, whether or not you want to provision and apply them as software or treat them as you'd treat any other server hardware in your environment," says Chris Steffen, principal technical architect for Kroll Factual Data, and an early adopter of Hyper-V. Kroll has 600 virtual machines using the Microsoft hypervisor and that number is growing. "We virtualize 85% of our production servers," Steffen says, adding that his next "holy grail" is to fully virtualize his database environment.
According to Steffen, Kroll has about 50 TB of storage on IBM FastT disk arrays, virtualized with Falconstor Software's IPStor software, and has decided to approach the virtualized arrays as it would physical devices. Hyper-V's already-supported file system makes that possible. "FalconStor's software was never a factor in deploying server virtualization, nor was IBM's hardware," he says. "It wasn't even a discussion." Steffen says Kroll also chose Hyper-V because of the price difference: about $10,000 for Hyper-V, with all virtual machine clients free, versus $50,000 to $60,000 for VMware ESX server.
While some industry observers argue that VMware's ESX server will become the data center operating system of the future, others think Hyper-V has a good chance of keeping the operating system the same as it ever was . . . at least in Windows shops. "Hyper-V's impact on the server virtualization market will be minimal at first," says Burton Group analyst Drue Reeves. "Its features won't be anywhere comparable to ESX … yet."
But Reeves predicts that Hyper-V will catch up in the long run. "We've seen it before with word processing," he says. "[Microsoft] Word was nowhere near as mature as WordPerfect at first, but Microsoft kept revving it, and eventually Word and Office took over that market."
Now that Microsoft has entered the hypervisor market, VMware may have to minimize the role of the operating system in favor of a bigger piece of the data center pie for the hypervisor. But according to Reeves, competitors like Virtual Iron Software could be in trouble if Hyper-V catches on. "Hyper-V is so cheap," he says. "It will also be something other host-based server virtualization systems like Sun's containers will have to contend with. I wouldn't be surprised to see Sun drop the containers and go for a hypervisor-based approach."
Operating systems are also "made and destroyed at independent hardware vendors," he says. "If Microsoft can get Hyper-V embedded in server hardware and booting off direct attached storage, everyone else at the low end of the market could be left out in the cold."
When it comes to Hyper-V, friction with storage vendors may arise over backup. Microsoft also has its own data backup proxy server, called Microsoft System Center Data Protection Manager (DPM), which is based on VSS snapshots. A scaled-back free snapshot service is also available as part of Windows Server 2008, under the label Windows Server Backup.
Most storage vendors will nominally support DPM and Server Backup snapshots, but won't support managing them in the same repository as their own. "We're really in a competitive situation with DPM," says Jason Fisher, director of product management for Symantec.
Regardless of where you stand in the debates over VMFS and OS vs. hypervisor-based server virtualization, one thing seems certain: Storage capabilities, and compatibility, will play a key role in the competition among virtual server products in the coming months. "NetApp's announcement [with Citrix] is just the first of many like it from storage vendors," says Burton Group analyst Chris Wolf.
"Storage is the really interesting area for us from here on out," says Simon Crosby, chief technology offier of virtualization management for Citrix. "Differentiation [between virtual server products] is branching out into an ability to do disaster recovery and backup, and that all points back to storage."