Today, administrators installing software typically must ensure beforehand that it's certified to run with their particular hardware and operating systems, then configure and optimize it afterward.
The hidden benefit from virtualization is that users can unpack a ready-to-run collection of software components--operating system and all--and drop it onto a fresh, empty partition of the computer called a virtual machine. No muss, no fuss, no driver updates, no configuration file tweaking, no conflicts with other software.
Virtualization essentially lets the companies selling the software handle the tricky part and also provides a clean slate for installation.
There's one problem, however: Some software licensing plans aren't designed to accommodate such schemes, though that could eventually change.
One convert to the approach is Open Xchange, a server software company that lets customers download its software packaged into a virtual machine so they can quickly get to the evaluation stage. Within the next six months, the company plans to release software for production use, not just testing, said , executive vice president of marketing strategy.
"We send an image that (has) a complete stack of software preinstalled, set up and ready to go," Kusnetzky said. "We felt it would be an advantage in the competitive marketplace," he said, because without the virtual machine approach, "it took a level of expertise to install it."
Representatives from three powers in the virtualization realm--EMC subsidiary VMware,with its open-source software, and Microsoft with the proprietary --all believe at a minimum that the idea has potential.
But it's VMware, which leads the virtualization market, that's working hardest to make virtual machine-based installation a reality--and to make its underlying virtual machine technology the foundation of choice. It has a Web site where people can download sample virtual-machine-based packages from Oracle, IBM and others.
"The reasons it's going to become mainstream is you can now package your application with the operating system it really wants. You get the exact patch level and everything in the OS that you want," said VMware President Diane Greene. And it's particularly useful for small software companies that don't have engineers to support a wide variety of systems. "They don't have to necessarily port their software to every possible operating system and every possible version of the operating system."
In recent months, VMware started offering two free ways that customers can try out virtual-machine-based software packages, which it calls virtual appliances. First came VMware Player in 2005, good for desktop applications, such as an isolated partition for safely surfing the Internet. In February came part two: for server tasks.
Xen programmers are currently stabilizing their core virtual machine software, but virtual-machine-based installation will happen with Xen, too, predicted Simon Crosby,co-founder and chief technology officer. "That's equally possible in Xen...I definitely think it's going to happen," Crosby said, though he acknowledged Xen doesn't yet have VMware's mature virtual machine management software or established presence at many customer sites.
Not so fast, cautions Illuminata analyst Gordon Haff. "This is a direction, but not a near-term mainstream change in the way that everyone installs their applications," Haff said. "There are too many details to work through. Licensing is one issue."
The licensing hurdle stems chiefly from the fact that the installation method requires the inclusion of an operating system, and although software companies might delight in distributing them willy-nilly, operating system companies are more finicky.
Microsoft, for example, permits only evaluation copies of Windows to be distributed, and then only within a company and only to test and evaluate software, said James Ni, group product manager for server virtualization at Microsoft.
"Currently there is no redistribution of the Windows Server operating system," Ni said. Right now, the virtual installation idea is about testing software rather than full-on production use, so the evaluation software approach is appropriate, Ni argued.
He's not alone in his assessment. "I would expect this to be primarily about experimentation," said Forrester analyst Frank Gillett.
Ni didn't close the door to virtual-machine-based software sales. Market forces dictated major changes to Microsoft licensing policies before. For example, Microsoft in 2004 began charging the, and in 2005 started permitting customers with one license for Windows Server 2003 Enterprise Edition to run as many as four copies on a single server partitioned with virtual machine software.
But Microsoft's policy is an impediment to VMware's aspiration. Greene sees companies distributing virtual-machine-based software internally today and expects customers will eventually buy it that way, Greene said.
"Microsoft is not letting their operating system be used in this model," Greene said. And though it's had a more permissive position in the past, it has backed off that stance: "Microsoft did not renew our license to (redistribute) Windows."
Open-source software, of course, has fewer restrictions. "Linux makes it easy," Gillett said.
Free versions of Linux are abundant, but distributing premium products from the two Linux market leaders isn't simple. Thus, Kusnetzky said, "It's wise to have a partnership with Red Hat or Novell," which is a move that Open-Xchange has made.
Not just the operating system
Microsoft, Xen and VMware virtualize a computer's hardware. But some companies tackling the problem at a higher level are offering a different revamp of software installation.
sells a product called Virtuozzo that essentially virtualizes the operating system rather than the underlying hardware. That lets several programs run at once in separate zones on one instance Linux or Windows. Sun Microsystems has taken the same approach with its "containers" technology in Solaris 10.
"We have templates for close to 100 different solutions and applications for various configurations," said SWsoft Chief Executive Serguei Beloussov. "When you apply a template to a certain virtual private server (a partition), this solution will immediately become available."
The company has partnerships to distribute prepackaged templates of Web server software and is working on new partnerships to offer software for more powerful servers as well, he said.
Softricity is another company that tries to break the hard link between operating system and applications. Its software first captures all the modifications a software package makes to Windows, letting companies store employees' configurations on a central server rather than directly modifying a PC and potentially causing conflicts among different programs.
"The applications are no longer bound to the operating system," said David Greschler, co-founder and vice president of corporate marketing. That lets administrators quickly set up new PCs or update existing ones, he said. It also means employees can move from one PC to another without disruption, because their software is automatically enabled when they log on to a new PC.
Yet another complication comes from the fact that VMware, Xen and Microsoft use a different file format for their virtual machines. In August, . That was shortly after Microsoft began offering royalty-free licenses to use its format, called Virtual Hard Disk. And Xen uses a third format, XVM.
Barriers between these formats are not insurmountable. For example, XenSource licensed Microsoft's VHD and will offer the ability to import virtual machines created with Microsoft Virtual Server, Crosby said, and VMware shared its format as well. At the same time, VMware offers support for that feature with its Virtual Machine Importer software.
But they're barriers nonetheless. "It will tend to retard the movement toward a standard hypervisor level that just sits on top of x86 hardware," Haff said, adding that low barriers would mean customers could more easily substitute one virtualization company's product for another. "It is not in VMware's (or Microsoft's) business interest to be able to have someone's free, native hypervisor just slip in to replace ESX Server."
Another hitch stems from cultural obstacles to virtualization in general, Red Hat Chief Executive Matthew Szulik said. "The customers I've talked to over the last six months are challenged by the human issues: How will they deal with the sharing of physical resources across the enterprise? We've all gotten conditioned to having our own server environments," he said.
Virtual installation will happen, but XenSource's Crosby understands the change won't happen overnight, "I think it's going to be a fairly profound change for the industry to get there."