Berkeley Univ. CS Dept.

TI RAID-II: A Scalable Storage Architecture for High-Bandwidth
Network File Service 

OR UCB 
LT CSD 92672 
AU Edward K. Lee 
AU Peter M. Chen 
AU John H. Hartman 
AU Ann L. Chervenak Drapeau 
AU Ethan L. Miller 
AU Randy H. Katz 
AU Garth A. Gibson 
AU David A. Patterson 

AB RAID-II (RAID the second) is a scalable high-bandwidth network
file server for heterogeneous 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 IO 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 mechisms for high-bandwidth and
low-latency IO requests; implements a RAID level 5 storage
system; and runs LFS, the Log-Structured File System, which is
specifically designed to support high-bandwidth IO and RAID level
5 storage systems.