This paper describes the collection and analysis of supercomputer I/O traces and their use in a collection of buffering and caching simulations. This serves two purposes. First, it gives a model of how individual applications running on supercomputers request file system I/O, allowing system designers to optimize I/O hardware and file system algorithms to that model. Second, the buffering simulations show what resources are needed to maximize the CPU utilization of a supercomputer given a very bursty I/O request rate. By using read-ahead and write-behind in a large solid-state disk,one or two applications were sufficient to fully maximize a Cray Y-MP CPU.

This paper describes the collection and analysis of supercomputer I/O traces on a Cray Y-MP. Analyzing these traces, which came primarily from programs with high I/O requirements, shows the fde system !/O patterns that these applications exhibit.

This paper describes the collection and analysis of supercomputer I/O traces and their use in a collection of buffering and caching simulations. This serves two purposes. First, it gives a model of how individual applications running on supercomputers request file system I/O, allowing system designers to optimize I/O hardware and file system algorithms to that model. Second, the buffering simulations show what resources are needed to maximize the CPU utilization of a supercomputer given a very bursty I/O request rate.