RAID-II: a high-bandwidth network file server
Ann L. Drapeau, Ken W. Shirriff, John H. Hartman, Ethan L. Miller, Srinivasan Seshan, Randy Howard Katz, Ken Lutz, David A. Patterson, E. K. Lee, P.M. Chen, Garth A. Gibson · 1994
In 1989, the RAID group at U. C. Berkeley built a prototype disk array called RAID-I. The bandwidth achieved by RAID-I was severely limited by the memory system bandwidth limitations of the disk array's host workstation. As a result, most of the bandwidth available from the disks could not be delivered to clients of the disk array file server. We designed our second prototype, RAID-II, to deliver as much of the disk array bandwidth as possible to file server clients. A custom-built circuit-board disk array controller, called the XBUS board, connects the disks and the high-speed network directly, allowing data for large requests to bypass the server workstation. A single workstation may control several XBUS boards for increased bandwidth. RAID-II runs the Log-Structured File System (LFS) to optimize the performance of the disk array for bandwidth-intensive applications. The RAID-II hardware with a single XBUS controller board delivers 20 megabytes/second of I/O between the disks and hig...