Striping and buffer caching for software RAID file systems in workstation clusters

A software RAID file system is defined as a system that distributes data redundantly across an array of disks attached to each of the workstations connected to a high-speed network. This configuration provides higher throughput and availability compared to conventional file systems. In this paper, we consider two specific issues, namely the distribution of data among the cluster (i.e. striping) and buffer caching for such an environment. Through simulation studies, we compare the performance of various striping methods and show that, for effective striping in software RAID file systems, we must take advantage of its flexible nature. Furthermore, for buffer caching, we show that conventional caching schemes that have been developed for distributed systems are insufficient, and that the ExODP (Exclusively Old Data and Parity) scheme, which is presented in this paper, overcomes the limitations of the previously proposed schemes