Will they do Windows?

Linux isn't the only clustering option; some high-performance computing centers use clusters that run Microsoft Corp.'s Windows operating system.

That's the case for the Cornell Theory Center at Cornell University. When center officials started working with Windows clusters, the only options they had were Microsoft's NT File System and Distributed File System, said David Lifka, the center's chief technical officer. Officials run NT File System on file servers and use the Distributed File System to aggregate physical storage into one logical volume.

Microsoft's file systems have been able to sustain "some really incredible loads," he said. Officials previously ran the Andrew File System on an IBM Corp. SP system, but found that the file system would crash when users ran 128-way processing.

Although officials have been pleasantly surprised with the Windows file systems, Lifka would like more options. "We would like to see [IBM's General Parallel File System] available for Windows," he said. Center officials have talked to representatives of Panasas Inc. about a Windows version of the company's cluster file system.

Bob Lenard, IBM's worldwide director for Linux clusters, said a Windows version of the General Parallel File System isn't in the works, but added that IBM officials will monitor the market and respond as demands dictate. Larry Jones, vice president of marketing at Pan-asas, said a Windows version of the company's file system is not in near-term plans, but is possible.