sfs: A Parallel File System for the CM-5

This paper describes the creation of a Unix-compatible file system with highly scalable performance and size. The file system is on the CM-5 backed by a scalable array of disks. Using the Unix file system (UFS) from the SunOS 4.1.2 kernel as a base and modifying it to support Connection Machine (CM) operations, we have created a new file system, the scalable file system, or sfs. We discuss the CM operations we support, such as parallel reads and writes to the processing nodes of the Connection Machine, the use of NFS to support many partitions of processing nodes on the CM, support for very large file sizes (64-bit) and support for odd numbers of disk drives. The tradeoffs and decisions made during the course of this project as well as performance data for varying numbers of disk drives are provided.