RELIABILITY MODELING OF DECLUSTERED-PARITY RAID CONSIDERING UNCORRECTABLE BIT ERRORS

Authors
Citation
Xf. Wu et al., RELIABILITY MODELING OF DECLUSTERED-PARITY RAID CONSIDERING UNCORRECTABLE BIT ERRORS, IEICE transactions on fundamentals of electronics, communications and computer science, E80A(8), 1997, pp. 1508-1515
Citations number
8
Categorie Soggetti
Engineering, Eletrical & Electronic","Computer Science Hardware & Architecture","Computer Science Information Systems
ISSN journal
09168508
Volume
E80A
Issue
8
Year of publication
1997
Pages
1508 - 1515
Database
ISI
SICI code
0916-8508(1997)E80A:8<1508:RMODRC>2.0.ZU;2-W
Abstract
UNcorrectable Bit Errors (UNBEs) are important in considering the reli ability of Redundant Array of Inexpensive Disks (RAID). They however, have been ignored or have not been studied in detail in existing relia bility analysis of RAID. In this paper. we present an analytic model t o study the reliability of declustered-parity RAID by considering UNBE s. By using the analytic model, the optimistic and the pessimistic est imates of the probability that data loss occurs due to an UNBE during the data reconstruction after a disk failed (we call this DB data loss ) are obtained. Then, the optimistic and the pessimistic estimates of the Mean Time To Data Loss (MTTDL) that take into account both DB data loss and the data loss caused by double independent disk failures (we call this DD data loss) are obtained. Furthermore, how the MTTDL depe nds on the number of units in a parity stripe, rebuild time of a faile d disk and write fraction of data access are studied by numerical anal ysis.