Construction of Sector-Disk (SD) Codes with Two Global Parity Symbols

Sector-Disk (SD) codes are erasure codes that address the mixed failure mode of current RAID systems. Rather than dedicate entire disks to erasure coding, as done in RAID-5, RAID-6 and Reed-Solomon coding, an SD code dedicates entire disks, plus individual sectors to erasure coding. The code then tolerates combinations of disk and sector errors, rather than solely disk errors. It has been an open problem to construct general codes that have the SD property, and previous work has relied on Montecarlo searches. In this paper, we present a general construction that addresses the case of any number of failed disks and in addition, two erased sectors. This result generalizes previous constructions extending RAID 5 and RAID 6.

By: Mario Blaum, James S. Plank

Published in: RJ10511 in 2013


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