Toward comprehensive and accurate simulation performance prediction of parallel file systems

We present the design and implementation of FileSim, a simulation framework with detailed models of parallel file systems, capable of reproducing the complex I/O behavior at scale. FileSim aims to support comprehensive and accurate end-to-end I/O performance prediction and evaluation of exascale high-end computing systems. To this end, FileSim provides several key features, including detailed, pluggable models of contemporary parallel file systems, the support of trace-driven simulation, and the capability of running large-scale I/O systems using parallel and distributed simulation.We conducted extensive validation and performance studies, through which we show that the simulator is capable of reproducing important I/O system behaviors comparable to those measured from the real systems. We demonstrate the capabilities of FileSim as a tool for exploring the parameter space and design alternatives of large-scale parallel file systems.