【摘要】 设计并实现了一种新型的多版本文件系统——HFS。HFS 把启发式规则和用户规则结合起来,提供灵活的版本保留策略,为必要的文件保留必要的版本,节省了存储空间。同时,还通过写时复制和目录版本等技术,进一步降低对存储资源的消耗。分析表明,该系统可以在保证数据可靠性的同时,有效地提高存储资源的利用率。HFS 的实现基于 Ext3,对 HFS 和 Ext3的文件读写性能的测试和比较的结果表明,HFS 的顺序读文件的性能与 Ext3相当,顺序写文件的性能和随机读写的性能比 Ext3降低了2%～5%,版本机制对文件系统性能的影响很小。更多还原

【Abstract】 This paper proposes a new prototype of versioning file system,named Hao’s file system (HFS).The system com- bines the heuristic rule with the user rule to establish a flexible retention policy,keeping necessary versions for necessary files and reducing space consumption.Furthermore,it makes good use of storage resource through the copy-on-writing technology and the directory versioning mechanism.The analysis showed that the HFS could enhance storage efficiency effectively while providing guaranteed data reliability.It was also proved by experiment that the HFS had little impact on file system performance compared with its ancestor,Ext3.The sequential reading performance of HFS was almost the same as that of Ext3,while the sequential writing performance and the random access performance were reduced by 2% ～5% compared with the Ext3.更多还原