Institute of Electrical & Electronic Engineers
Large scale storage systems require multi-disk fault tolerant erasure codes. Replication and RAID extensions that protect against two- and three-disk failures offer a stark tradeoff between how much data must be stored, and how much data must be read to recover a failed disk. Flat XOR-codes - erasure codes in which parity disks are calculated as the XOR of some subset of data disks - offer a tradeoff between these extremes. In this paper, the authors describe constructions of two novel flat XOR-code, stepped combination and HD-combination codes.