SANTOPIA: SHARED-DISK FILE SYSTEM FOR STORAGE CLUSTER

摘要

Recently, there have been large storage demands for manipulating multimedia data such as image and video. To resolve tremendous storage demands, one of the major researches is the SAN (Storage Area Network) that provides the local file requests directly from shared disk storage and also eliminates the server bottlenecks to performance and availability. The SAN also improves the network latency and bandwidth through new channel interface like FC (Fibre Channel). The FC is capable of maintaining several simultaneous gigabit data transfer. But to make use of the efficient storage network like SAN, a traditional file system is not adaptable in terms of scalability, availability and consistency issues. Therefore, we propose the new shared-disk file system, the so-called SANtopia File System, for share disk storage that manipulates the large-scale inode objects and provides a key cluster enabling technology for Linux, helping to bring the scalability, availability, and load balancing benefits of clustering to Linux. In this paper, we describe the architecture and design issues of a shared-disk file system for shared disk storage and provide the efficient bitmap, the extent-based semi flat structure and the two-phase directory structure of using Extendible Hashing. And we also present a cache coherence protocol using buffer forwarding scheme to maintain the efficient metadata consistency. At last, we evaluate the performance in terms of average response time and I/O rate.