Microsoft Windows on a mainframe?

Software that for the first time lets users run native copies of the Windows operating systems on a mainframe will be introduced Friday by data center automation vendor Mantissa.

The company's z/VOS software is a CMS application that runs on IBM's z/VM and creates a foundation for Intel-based operating systems.

Users only need a desktop appliance running Microsoft's Remote Desktop Connection (RDC) client, which is the same technology used to attach to Windows running on Terminal Server or Citrix-based servers.

Users will be able to connect to their virtual and fully functional Windows environments without any knowledge that the operating system and the applications are executing on the mainframe and not the desktop.

According to the company's Web site, users will be able to create a PC in 15 seconds, have it operational in 15 minutes and use it once or have it permanently without worrying about depreciation of hardware.

Because z/VOS supports x86 architectures, the technology also can run Linux images.

The z/VM hypervisor already natively supports the ability to run hundreds to thousands of Linux servers on a single mainframe.

Mantissa is attempting to match that performance for Windows via z/VOS.

The company says z/VOS will eliminate the need to acquire and maintain desktop hardware and costs associated with PCs such as high power consumption.

“The product has been a bear for the development group but the thought of being able to run 3,000 copies of Windows on one System z so fascinated the team that we needed very little additional incentive,” Mantissa CEO and founder Gary Dennis said on the IBMVM list serve site last summer when he introduced the z/VOS concept.

Dennis did not respond to inquires asking for comment on this story.

He is scheduled to introduce z/VOS Friday at the annual Share conference in Austin, Texas, during a presentation entitled “x86 Virtualization Technology for System z.”

Mantissa says z/VOS will be the cornerstone of what it calls its utility virtualization product line.

“To my knowledge this has never been done on a mainframe, but always on some other kind of terminal server with an Intel architecture and not System z,” says Clay Ryder, president of the Sageza Group. “I could see for schools or fixed function workstations. It would be terrific in there is nothing to touch and you can deploy those devices and everything takes place in one central location. As students or users leave, files can be cleaned or archived or whatever and from an administrative point of view that is a real plus.”

But Ryder says the concept doesn't come without questions.

“What is the magic seat count number where it makes more sense to do this on a mainframe. And the Z is not the kind of machine people have laying around. There is certainly a lot to think about here,” he says.

Another issue is the System z was designed originally to do transaction processing not the kind of workloads that are done on PCs today.

“But that said, the Z is a very powerful and fast system,” Ryder says. He says the design of the z9 and z10 and off-load engines in the mainframe such as the Integrated Facility for Linux (IFL) make it likely the system could take on some workloads not anticipated in the system's traditional design.

Users who responded to Mantissa CEO Dennis when he floated the concept last summer approached the idea with intrigue and questions.

“We can hope that the version of Windows will be more stable than Windows Vista. Moving that kind of instability into z/VM is not particularly attractive. Otherwise, on a conceptual basis, it opens up many possibilities,” said a discussion participant named John Baker.

Others speculated that the technology might work better for server applications that have fewer GUI requirements that could tax the mainframe.

“Most likely this would be to run things such as MS SQL Server, MS Exchange and other 'server' software. Not an end-user GUI session. Just like most z/Linux users are not running X applications. They are running 'servers' such as e-mail, web, WAS, etc,” wrote poster John McKown.

The little information available on z/VOS from Mantissa doesn't give any hint whether the software will support both the Windows client and server operating systems.

In terms of licensing issues, Mantissa's Dennis doesn't see anything out of the ordinary with current virtualization licensing.

“We don't see anything in the Microsoft EULA that would permit or cause them to treat this environment any different than existing VM environments. This environment should work in their favor since the images (and therefore the licenses) can be deployed more efficiently than in a blade warehouse environment,” Dennis wrote on the discussion list.