中文摘要：

建立独立于具体算法的复本存储模型,识别影响效率的关键参数和无关参数;分析系统规模增长对效率的影响,通过实验得出空间效率与I/O效率的乘积同系统节点数量近似成反比这一结论,并从理论上解释结论背后的成因。研究结果可用于指导复本存储机制的工程应用,为空间效率和I/O效率之间的权衡以及大规模存储系统I/O性能的预测提供理论依据。

英文摘要：

An algorithm-independent description model was established for the mechanism, and both efficiency-related and efficiency-independent parameters were identified. Besides, the impact of system scale on efficiency was investigated, and an important observation was obtained that the product of the two utilization ratios （i.e., the utilization ratio of disk space and that of I/O bandwidth） is approximately inversely proportional to the number of nodes contained in the system. The observation was verified through experituental results, and the reason behind was revealed through theoretical analy- sis. The study provides guidelines for the application of replication-based storage mechanism in engineering, and lays a theoretical foundation for the trade-off between the two utilization ratios and for the prediction of I/O performance inlarge-scale storage systems.