Bridging the Gap Between Parallel File Systems and Local File Systems: A Case Study with PVFS

Parallel I/O plays an increasingly important role in today's data intensive computing applications. While much attention has been paid to parallel read performance, most of this work has focused on the parallel file system, middleware, or application layers, ignoring the potential for improvement through more effective use of local storage. In this paper, we present the design and implementation of segment-structured on-disk data grouping and prefetching (SOGP), a technique that leverages additional local storage to boost the local data read performance for parallel file systems, especially for those applications with partially overlapped access patterns. Parallel virtual file system (PVFS) is chosen as an example. Our experiments show that an SOGP-enhanced PVFS prototype system can outperforma traditional Linux-Ext3-based PVFS for many applications and benchmarks, in some tests by as much as 230% in terms of I/O bandwidth.