RAMA: An Easy-to-Use, High-Performance Parallel File System

Modern massively parallel file systems provide high bandwidth file access by striping files across arrays of disks attached to a few specialized I/O nodes. However, these file systems are hard to use and difficult to integrate with workstations and tertiary storage. RAMA addresses these problems by providing a high-performance massively parallel file system with a simple interface. RAMA uses hashing to pseudo-randomly distribute data to all of its disks, insuring high bandwidth regardless of access pattern and eliminating bottlenecks in file block accesses. This flexibility does not cause a large loss of performance — RAMA’s simulated performance is within 10-15% of the optimum performance of a similarly-sized striped file system, and is a factor of 4 or more better than a striped file system with poorly laid out data.