@InProceedings{stodolsky:logging,
  author = {Daniel Stodolsky and Garth Gibson and Mark Holland},
  title = {Parity Logging: Overcoming the Small Write Problem in Redundant Disk
  Arrays},
  booktitle = {Proceedings of the 20th Annual International Symposium on
  Computer Architecture},
  year = {1993},
  pages = {64--75},
  earlier = {stodolsky:logging-tr},
  later = {stodolsky:jlogging},
  URL =
  {http://www.cs.cmu.edu/afs/cs.cmu.edu/project/pdl/ftp/ParityLogging/ISCA93.ps},
  keywords = {parallel I/O, RAID, redundancy, reliability, disk array,
  pario-bib},
  abstract = {Parity encoded redundant disk arrays provide highly reliable,
  cost effective secondary storage with high performance for read accesses and
  large write accesses. Their performance on small writes, however, is much
  worse than mirrored disks - the traditional, highly reliable, but expensive
  organization for secondary storage. Unfortunately, small writes are a
  substantial portion of the I/O workload of many important, demanding
  applications such as on-line transaction processing. This paper presents
  parity logging, a novel solution to the small write problem for redundant
  disk arrays. Parity logging applies journalling techniques to substantially
  reduce the cost of small writes. We provide a detailed analysis of parity
  logging and competing schemes - mirroring, floating storage, and RAID level 5
  - and verify these models by simulation. Parity logging provides performance
  competitive with mirroring, the best of the alternative single failure
  tolerating disk array organizations. However, its overhead cost is close to
  the minimum offered by RAID level 5. Finally, parity logging can exploit data
  caching much more effectively than all three alternative approaches.},
  comment = {Cite stodolsky:jlogging. Earlier version is CMU-CS-93-200. Parity
  logging to improve small writes. Log all parity updates; when it fills, go
  redo parity disk. Actually distribute the parity and log across all disks.
  Performance is comparable to, or exceeding, mirroring. Also handling double
  failures.}
}