一种可行的优化降级读性能RAID-6编码算法

Efficient RAID-6 MDS code for degraded reads optimization

随着大数据时代的来临以及存储规模的不断扩大,现代数据中心对存储系统的可靠性要求越来越高。针对传统RAID-6纠删码存储系统在降级模式下读操作性能不足的问题,提出一种优化降级读性能的RAID-6编码算法。利用水平码中连续数据元素更有可能共享相同水平校验链的特点,将X-码中对角校验链上数据元素的布局方式调整为水平方向,保持校验元素的位置及其计算方法不变,有效减小了降级读操作的额外I/O开销。仿真结果表明,优化X-码在磁盘数量相同的情况下降级读性能优于RDP码和X-码。

With the coming of Big Data Era and the development of modern storage systems, there is a big challenge in the reliability of storage systems in modern data center. Due to the fact that most classic RAID-6 MDS codes have limitations on degraded reads, a new RAID-6 MDS erasure code for optimizing the degraded reads is proposed, which adjusts the diagonal layout of X-code to horizontal direction by taking advantage of horizontal codes while the continuous data elements are more likely to share the same horizontal parity chain for optimizing degraded reads. Experimental results show that the optimized X-code can efficiently reduce the additional I/O requests for degraded read operations. Especially, compared with RDP code and X-code, the optimized X-code can obtain an improved performance with the same number of disks.