RAID-II: A Scalable Storage Architecture for High-Bandwidth Network File Service
Edward K.F. Lee, Peter M. Chen, John H. Hartman, Ann L. Drapeau, Ethan L. Miller, Katz, Randy H, Author, Garth A. Gibson, David A. Patterson · UC Berkeley
RAID-II (RAID the second) is a scalable high-bandwidth network file server for heterogenous computing environments characterized by a mixture of high-bandwidth scientific, engineering and multi-media applications and low-latency high-transaction-rate UNIX applications. RAID-II is motivated by three observations: applications are becoming more bandwidth intensive, the I/O bandwidth of workstations is decreasing with respect to MIPS, and recent technological developments in high-performance networks and secondary storage systems make it economical to build high-bandwidth network storage systems. Unlike most existing file servers that use a bus as a system backplane, RAID-II achieves scalability by treating the network as the system backplane. RAID-II is notable because it physically separates files service, the management of file metadata, from storage service, the storage and transfer of file data; stripes files over multiple storage servers for improved performance and reliability; provides separate mechanisms for high-bandwidth and low-latency I/O requests; implements a RAID level 5 storage system; and runs LFS, the Log-Structured File System, which is specifically designed to support high-bandwidth I/O and RAID level 5 storage systems