I/O Interference Alleviation on Parallel File Systems Using Server-Side QoS-Based Load-Balancing

Abstract

Storage performance in supercomputers is variable, depending not only on an application’s workload but also on the types of other concurrent I/O activities. In particular, performance degradation in meta-data accesses leads to poor storage performance across applications running at the same time. We herein focus on two representative performance problems, high load and slow response of a meta-data server, through analysis of meta-data server activities using file system performance metrics on the K computer. We investigate the root causes of such performance problems through MDTEST benchmark runs and confirm the performance improvement by server-side quality-of-service management in service thread assignment for incoming client requests on a meta-data server.