Using file system counters in modelling parallel I/O architectures

Keeping compute and I/O performance balanced is a major challenge for future cost-efficient HPC systems. Several architectural concepts and new technologies allow to address this challenge, however at the price of higher complexity. As a result, the need emerges to simulate these architectural concepts and new technologies to predict their impact on the overall performance. In this paper we propose a particular approach to explore the design space using event simulation models that take I/O server-side performance counters as input. In this way large quantities of real-life data measured over a large number of applications can be used to explore architectural modifications. We apply our approach using data collected by a GPFS file system serving a petascale Blue Gene/P installation.