V Code : An Efficient Coding Scheme for Correcting Twice Storage Node Failures

Proper data placement schemes based on erasure correcting code are one of the most important components for a highly available data storage system. In this paper,a new class of array codes are introduced which is called the V codes. The V codes are an binary maximum distance separable (MDS) codes and correct various double node failures,i.e. minimum column distance 3 and thus is optimal in terms of node failure recovery capability for a given data redundancy. We provide detailed v code's decoding algorithms for correcting various double node failures. We show that the decoding complexity of the V codes is much lower than those of the existing comparable codes, thus the V codes are practically very meaningful for storage systems that need higher reliability.