As a major Linux vendor, one might expect that Red Hat's new Red Hat Enterprise Virtualization (RHEV) for Servers solution would be able to run on Linux servers.

You'd be wrong. Not only is that not the case, but the Management Server piece of RHEV, which provides virtualization management capabilities, requires users to be running Microsoft's Windows Server.

That's no typo: A Linux vendor is requiring its users to run one of its key new products on the rival, closed source Windows operating system.

According to Red Hat, the plan is to have a Linux version ready by some point in 2010. But in the meantime, Red Hat customers who want to run the virtualization manager must purchase or already own a Windows server.

"The Windows Server could be running as a virtual server in RHEL (Red Hat Enterprise Linux), but you would require a Windows machine for the management system," Andy Cathrow, product marketing manager for Red Hat Enterprise Virtualization, told InternetNews.com. "We spent a lot of time talking to customers to see what their view was on this and I think with the possible exception of Red Hat, everyone has some Windows in their datacenter."

Cathrow added that even though it is a requirement for running the management system, Red Hat would not be reselling Windows Server. Instead, he noted that it is the customers' own responsibility to acquire the required Windows Server.

While Red Hat won't be reselling Windows Server, it and Microsoft do have an interoperability agreement enabling each other's respective virtualization technologies.

How this happened

The story of how Red Hat ended up shipping a Windows Server application to manage Linux virtualization starts with the root technology on which RHEV is built. In 2008, Red Hat acquired virtualization vendor Qumranet for $107 million. Part of the Qumranet technology portfolio was a virtualization management technology called SolidICE, which was built for Windows.

Cathrow said that SolidICE had great features but was missing some server virtualization components.

"So we extended the SolidICE product and built on the Qumranet base, which has been out in the market and deployed with customers," Cathrow said. "We're in the process of moving it to a fully Linux and open source base, but it was important for us to bring this to market quickly for our customers."

Cathrow added that Red Hat decided to go to market with the enhanced Qumranet solution while work remains ongoing on building a Linux port using an open source effort.

In addition to the Windows Server requirement, users will also need to have a Windows desktop (XP or higher) in order to view the Red Hat Enterprise Virtualization Manager console. Cathrow noted that the console uses Microsoft's .NET Web Presentation Framework (WPF) to run.

Red Hat is also working on a multiplatform Web-based user console, but it, too, is not yet available.

WPF and other Microsoft .NET capabilities are available to Linux users under the auspices of the Novell-led Mono project. But according to Cathrow, Mono was not a route that Red Hat wanted to go for deploying its management server or console products.

"We need to make the transition to open technologies such as Java quickly and there is work to get a .NET application to run in Mono anyways," Cathrow said. "Anything that is written in Mono will run anywhere, but if something is written in .NET on Windows, there is no guarantee it will work on Mono on Linux."

As Red Hat builds out its Linux version of the Virtualization Management server, Cathrow noted that there will be an easy migration path for users of the Windows version. He added that with Red Hat's subscription model, subscribers get new versions as they are made available.

"Anytime we acquire a company, there is work to go from a proprietary code base to open source," Cathow said. "So you'll absolutely see the whole RHEV suite on an open source model next year."