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
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.