A multiple disk failure recovery scheme in RAID systems

Abstract

In this paper. we propose a practical disk error recovery scheme tolerating multiple simultaneous disk failures in a typical RAID system. resulting in improvement in availability and reliability. The scheme is composed of the encoding and the decoding processes. The encoding process is defined by making one horizontal parity and a number of vertical parities. The decoding process is defined by a data recovering method for multiple disk failures including the parity disks. The proposed error recovery scheme is proven to correctly recover the original data for multiple simultaneous disk failures regardless of the positions of the failed disks. The proposed error recovery scheme only uses exclusive OR operations and simple arithmetic operations, which can be easily implemented on current RAID systems without hardware changes. (C) 2003 Elsevier B.V. All rights reserved.