中文摘要：

以数据节点与网络链路的可靠性因素分析为基础,提出了云存储系统的数据副本服务可靠性模型.根据访问可靠性与数据副本数量、用户访问量之间的关系,设计数据服务可靠性、副本生成时机、存储节点选择的确定方法,实现了副本分布、删除算法,并在云存储系统ERS-Cloud上进行一系列实验,结果表明该方法能够有效保障数据服务的可靠性,进一步降低副本的冗余存储数量.

英文摘要：

The reliability of data-nodes and the reliability of relevant network links were analyzed, and then the reliabilitymodel of replica service of cloud storage systems was constructed. According to the relationships among access reliability,the number of replicas and the number of user＇s accesses, the reliability of data service and the trigger mechanism of rep-lica generation were presented, and the storage node selection was aptly checked, then the replica distribution algorithmand replica deletion algorithm were proposed. Finally a series of experiments were conducted in the cloud storage system,named ERS-Cloud, and the results indicate that the approach can ensure the reliability of data service, and further de-crease the number of replicas of the redundant storage.