Cray Compute Node Linux

Unix, and now Linux, havebecome prevalent in high-performance computing (HPC) systems, including systems at the very high end. These operating systems were not originally intended for scalable HPC usage, but have been adapted to fulfill that role, while preserving their ability to support a wide range of applications and use cases. While Cray Research and some related commercial efforts had started with proprietary operating systems, Unix or Linux was eventually chosen to provide this wider applicability. This chapter describes the evolution of the use of Unix and Linux at Cray, along with similar activities at two other companies that followed similar paths, BBN Advanced Computers Inc. and Tera Computer Company (later merged with Cray to form Cray Inc.).