Parity striping of disc arrays: low-cost reliable storage with acceptable throughput
Jim Gray, Bob Horst, Mark Walker · 1990
Abstract: ~n analysis of mirrored discs and of RAID5 shows that mirrors have considerably better throughput, measured as requests/second, on random requests of arbitrary size (up to 1MB). Mirrors have comparable or better response time for requests of reasonable size (less than looKB). But mirrors have a 100 % storage penalty: storing the data twice. Parity striping is a data layout that stripes the parity across the discs, but does not stripe the data. Parity striping has throughput almost as good as mirrors, and has costlGB comparable to RAIDS designs-- combing the advantages of both for high-traffic disc resident data. Parity striping has additional fault containment and software benefits as well. Parity striping sacrifices the high data transfer rates of RAID designs for high throughput. It is argued that response time and throughput are preferable performance