云灾备的数据修复技术

[摘要] 基于纠错码的云灾备系统的关于降低修复带宽的最新研究成果，文章讨论了云灾备系统中存储节点失效的修复问题。文章指出数据修复问题有3种模型：精确修复、功能修复和系统部分精确修复。在精确修复中，失效的模块需要修复精确的丢失编码包；在功能修复中，新产生的编码包可以包含不同于丢失节点的数据，只要修复的云灾备系统支持最大可分离距离（MDS）码属性。系统部分精确修复是精确修复和部分修复的之间的一个混合的修复模型。

[关键词] 云灾备；纠错码；网络编码；数据修复

[Abstract] In this paper, we discuss latest research on cloud disaster recovery systems based on an erasure code that reduces repairing bandwidth. We also discuss problems with repairing in cloud disaster recovery systems when there is storage node failure. Three models for addressing the repairing problem are proposed: exact repair, functional repair, and exact repair of systematic parts. In exact repair, the failed blocks are exactly regenerated. In functional repair, the newly generated blocks can contain data different to that of the failed node as long as the repaired system maintains the MDS code property. Exact repair of the systematic part is a hybrid repair model and lies between exact repair and functional repair.

[Keywords] cloud disaster recovery; erasure codes; network coding; information recovery