一种改进的块级连续数据保护机制  

An Improved Block-Level Continuous Data Protection Mechanism

作　　者：李旭[1,2] 谢长生[1] 杨靖[1] 曹强[1] 魏沁祺[1] 

机构地区：[1]华中科技大学计算机科学与技术学院武汉光电国家实验室,武汉430074 [2]中冶南方工程技术有限公司信息网络中心,武汉430223

出　　处：《计算机研究与发展》2009年第5期762-769,共8页Journal of Computer Research and Development

基　　金：国家“九七三”重大基础研究发展计划基金项目(2004CB318203);国家自然科学基金项目(60603074,60603075)~~

摘　　要：随着存储技术的快速发展,连续数据保护(CDP)功能已成为现代存储系统重要的数据保护和恢复手段.根据当前不同CDP实现机制的优缺点,提出了一种基于TRAP-4的改进机制——ST-CDP.在保留TRAP-4原有数据记录方式的基础上,按一定间隔值d在恢复链条中插入对应时间点的快照数据,有效地解决了TRAP-4的链条易失效和恢复时间过长问题.借助量化分析模型分析了该机制的性能并确定最优的d值.原型系统在Linux内核块设备层的RAID5上实现了该机制,并通过实验对3种不同CDP机制进行对比测试.实验结果表明ST-CDP既具有与TRAP-4类似比快照机制存储开销低、系统性能影响小的优点,还具有比TRAP-4更快的恢复效率及更高的可靠性.因此ST-CDP是一种高效并且恢复成本较低的连续数据保护机制.With the rapid development of storage technology, continuous data protection （CDP） has become an important data protection and recovery method for modern data storage systems now, According to the merits and shortcomings of existing CDP mechanism, an improved mechanism based on TRAP-4 （timely recovery to any point-in-time） is provided. It reserves the basic data logging method of TRAP-4 first, and then inserts a few snapshot data into the recovery chain by a certain interval values d. This mechanism can not only avoid the latentrecover chain crash problem, but also can shorten the data recovery time greatly. A quantitative mathematical model is used to analyze its performance and calculate an optimal d value for ST-CDP. This prototype system of block level ST- CDP mechanism has been implemented in a Linux block level device （MD RAID 5 device for Linux kernel）. Contrastive experiments among three different CDP mechanisms are presented. The performance test results show that ST-CDP not only have lower storage space overhead and less infection to the storage system than those of the traditional snapshot mechanisms, but also have higher recovery efficiency and reliability than TRAP-4. It is affirmed that ST-CDP is an efficient continuous data protection mechanism with very low recovery cost.

关 键 词：连续数据保护 快照 数据备份 可靠性 存储系统 

分 类 号：TP333[自动化与计算机技术—计算机系统结构]