Shared File Systems and Fibre Channel

Shared file systems like Cray's SFS, DEC's VAXcluster file system, and Oracle's Parallel Server exploit network-attached storage by creating serverless distributed file systems that allow efficient, simultaneous access to shared, network-attached storage devices. In the past, these shared file system designs relied on proprietary networkattached storage like DEC's CI network or higher-cost interfaces like HiPPI, or used software to emulate shared storage networks. With the advent of Fibre Channel, a highvolume, open standard in network-attached storage interfaces is now available. In this paper we will review past work in traditional distributed file systems like NFS and AFS and work in shared file systems by Cray, DEC, CMU and others. New file system architectures for shared network storage will also be described. We will give a brief overview of Fibre Channel technology, describing its protocol layers, how higher level protocols like IP and SCSI are mapped to this protocol, and the topologies supported. Finally we will sketch the future evolution of network-attached storage as it moves from high-end, high-capacity requirements into mid-range and lowerend desktop computing. We believe these trends may be affected by Fibre Channel’s potential to function as both a network and storage interface.