Performance of the Vesta parallel file system

Vesta is an experimental parallel file system implemented on the IBM SPI. Its main features are support for parallel access from multiple application processes to file, and the ability to partition and re-partition the file data among these processes. This paper reports on a set of experiments designed to evaluate Vesta´s performance. This includes basic single-node performance, and performance using parallel access with different file partitioning schemes. Results are that bandwidth scales with the number of I/O nodes accessed, and that orthogonal partitioning schemes achieve essentially the same performance. In many cases performance equals the disk hardware limit. This is often attributed to prefetching and write-behind in the I/O nodes