An Efficient Coding Scheme for Tolerating Double Disk Failures

A new MDS array erasure code, called DA-Code, which can tolerate double disk erasures for highly reliable data storage system is proposed in this paper. The DA-Code requires only XOR operations and achieves optimal encoding, updating and decoding complexity. The parity symbols are evenly distributed in the array, overcoming the bottleneck effects of repeated write operation. Detailed DA-Code´s decoding algorithm for correcting double disk failures is provided. Analysis result shows that the new coding scheme has excellent performance. Thus, the DA-Code is practically very meaningful for storage systems which need high reliability.