Analysis of HPSS performance based on per-file transfer logs

This paper analyses high performance storage system (HPSS) performance and, to a lesser extent, characterizes the San Diego Supercomputer Centre (SDSC) HPSS workload, utilizing per-file transfer logs. The performance examined includes disk cache hit rates, disk file open times, library tape mount times, manual tape mount times, transfer speeds and latencies. For workload characterization, we examine daily activity in terms of file counts for get and put, and total bytes transferred, as well as activity loads in 10-minute intervals. Our results largely confirm our expectations but provide more accurate and complete descriptions, with unexpected subtleties. The visual representations provide additional insights into the functioning of the system.