Parallel Simulation of Parallel File Systems and I/O Programs

Efficient I/O implementations can have a significant impact on the performance of parallel applications. This paper describes the design and implementation of PIOSIM, a parallel simulation library for MPI-IO programs. The simulator can be used to predict the performance of existing MPI-IO programs as a function of architectural characteristics, caching algorithms, and alternative implementations of collective I/O operations. We describe the simulator and presents the results of a number of performance studies to evaluate the impact of the preceding factors on a set of MPI-IO benchmarks, including programs from the NAS benchmark suite.