Design and analysis of a parallel file system for distributed shared memory systems

File accesses are usually sequentially performed in existing Distributed Shared Memory (DSM) systems. These sequential file accesses will result in the accumulation of input data at the node that handles file operations, generating a bottleneck at that node and a large amount of network traffic to move the input data to other nodes for execution. Although the file access time is often neglected in the performance evaluation of DSM systems, it is not ignored by programmers in real life. In this paper, we will describe the design and analysis of a parallel file system for DSM systems. File accesses are carried out in parallel and a modified file access mechanism is provided to reduce network traffic. Our analysis shows that the overall performance of some I/O-intensive DSM applications such as Successive Over Relaxation can be significantly enhanced with our design in the best case. To approach this best case, we have proposed two implementations. Both implementations employ variable-distribution schemes, which distribute file blocks on the disks according to the access pattern of the application. Keyword: Distributed Shared Memory, Parallel I/O, File Access Mechanism, Variable-Distribution Scheme