A maker of software that allows a single application to draw resources from multiple linked, or "clustered," servers said Monday that it has made available a version of its software for IBM's mainframe running the Linux operating system.Sistina Software has developed a clustered file system product called GFS (Global File System), which allows a single application such as a database to run on more than one physical server, and share data and computing resources between those servers as if it were a single system. In GFS version 5.1 for IBM's zSeries mainframe, the software will link an application to numerous "virtual servers" on the mainframe.Similar software has been a crucial feature in IBM's age-old mainframes running the Armonk, New York, company's OS\/390 operating system, said Joaqu\u00edn Ruiz, vice president of marketing and product development at Sistina, in Minneapolis, Minnesota."People expect this capability because they grew up on OS\/390. They want this same sort of functionality on Linux," Ruiz said.Sistina has enlisted Mainline Information Systems, a systems integrator that sells a large number of IBM's zSeries mainframes, to help customers implement the clustered file system software. IBM makes its own clustered file system software. However, it is more suited for running applications on multiple Intel-based servers, Ruiz said.\n\nSistina's GFS version 5.1 for the Mainframe is currently undergoing beta testing and is expected to be generally available through Mainline by the end of the year.