An NFS Trace Player for File System Evaluation
Ningning Zhu, Jiawu Chen, Tzi‐cker Chiueh, Daniel Ellard · Digital Access to Scholarship at Harvard (DASH) (Harvard University) · 2003
File access traces have been used to drive simulations of storage management algorithms such as file caching, for workload characterization and modeling, and to identify interesting access patterns for performance optimization. Surprisingly they are rarely used to test the correctness and evaluate the performance of an actual file system or server. The main reason is that up until now there did not exist a flexible and easy-to-use player for file access traces. This paper describes the design, implementation, and evaluation of an NFS trace play-back tool called TBBT (Trace-Based file system Benchmarking Tool) that can automatically derive the file system hierarchy from an NFS trace, initialize the file system image with controllable aging effects, and speed up or slow down the trace play-back speed using temporal or spatial scaling without violating dependencies among trace entries. Experiments using a large NFS trace set show that TBBT can indeed produce different throughput and latency measurements than synthetic benchmarks such as SPECsfs. Moreover, TBBT's trace player is actually more efficient than SPECsfs's workload generator despite the fact that the former requires more CPU computation and disk I/O accesses.