DR-nets: data-reconstruction networks for highly reliable parallel-disk systems

We propose DR-nets, Data-Reconstruction networks, to construct massively parallel disk systems with large capacity, wide bandwidth and high reliability. Each node of a DR-net has disks, and is connected by links to form an interconnection network. To realize the high reliability, nodes in a sub-network of the interconnection network organize a group of parity calculation proposed for RAIDs. Inter-node communication for calculating parity keeps the locality of data transfer in DR-nets, and it inhibits bottlenecks from occurring, even if the size of the network becomes very large. Overlapped two types of parity groups on the network make the system able to handle multiple disk-drive failures. A 5 × 5 torus DR-net recovers data 100% with two damaged disk drives located in any place, 95% with four damaged drives, and can recover with up to nine damaged drives.