Towards simulation of parallel file system scheduling algorithms with PFSsim

Many high-end computing (HEC) centers and commercial data centers adopt parallel file systems (PFSs) as their storage solutions. As the number of applications concurrently accessing a PFS grows in both quantity and variety, it is expected that scheduling algorithms for data access will play an increasingly important role in PFS service quality. However, it is costly and disruptive to thoroughly research scheduling mechanisms in deployed peta- or exascale systems, compounded by the complexity in scheduling policy implementation and experimental data gathering. While a few parallel file system simulation frameworks have been proposed (e.g., [1,2]), their goals have not been in the scheduling algorithm evaluation. In this paper, we propose PFSsim, a simulator designed for the purpose of evaluating I/O scheduling algorithms in PFS. PFSsim is a trace-driven simulator based on the network simulation framework OMNeT++ [23] and the disk system simulator DiskSim [21]. A flexible scheduler module is provided for scheduling algorithm deployment, and the system characteristics are highly configurable. We have simulated PVFS2 on PFSsim, and the experimental results show that PFSsim is capable of simulating the system characteristics and showing the performance of the scheduling algorithms.