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arXiv · 1310.2381

MDR Codes: A New Class of RAID-6 Codes with Optimal Rebuilding and Encoding

Yan Wang·Xunrui Yin·Xin Wang
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Abstract

As storage systems grow in size, device failures happen more frequently than ever before. Given the commodity nature of hard drives employed, a storage system needs to tolerate a certain number of disk failures while maintaining data integrity, and to recover lost data with minimal interference to normal disk I/O operations. RAID-6, which can tolerate up to two disk failures with the minimum redundancy, is becoming widespread. However, traditional RAID-6 codes suffer from high disk I/O overhead during recovery. In this paper, we propose a new family of RAID-6 codes, the Minimum Disk I/O Repairable (MDR) codes, which achieve the optimal disk I/O overhead for single failure recoveries. Moreover, we show that MDR codes can be encoded with the minimum number of bit-wise XOR operations. Simulation results show that MDR codes help to save about half of disk read operations than traditional RAID-6 codes, and thus can reduce the recovery time by up to 40%.

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Yan Wang, Xunrui Yin, Xin Wang. 2014-05-19. MDR Codes: A New Class of RAID-6 Codes with Optimal Rebuilding and Encoding. https://doi.org/10.1109/jsac.2014.140520

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