中文摘要：

E-mail： yinjinfu@gmail.com; Yin-Jin Fu received his B.S. degree in mathematics from Nan- jing University, China, and M.S. degree in computer science from Na- tional University of Defense Technology （NUDT）, Changsha, in 2006 and 2008, respectively. Now he is a Ph.D. candidate at the State Key Labora- tory of High Performance Computing in NUDT. His research areas are data deduplication, cloud storage, and distributed file systems. E-mail： nongxiao@nudt.edu.cn Corresponding Author; Nong Xiao received the B.S. and Ph.D. degrees in computer science from NUDT, Changsha, in 1990 and 1996, respectively. Now he is a pro- fessor in the State Key Laboratory of High Performance Computing in NUDT. His current research inter- ests include large-scale storage sys- tem, network computing, and com- puter architecture. E-mail： xkliao@nudt.edu.cn Xiang-Ke Liao received the B.S. degree in computer science from Tsinghua University, Beijing, and M.S. degree in computer science from NUDT, Changsha, in 1985 and 1988, respectively. Now he is a professor and the dean of the School of Computer in NUDT. His research areas are computer architecture, operating systems, and distributed systems. E-mail： liufang@nudt.edu.cn Fang Liu received the B.S. and Ph.D. degrees in computer science from NUDT, Changsha, in 1999 and 2005, respectively. Now she is an associate professor in the State Key Laboratory of High Performance Computing in NUDT. Her current research interests include distributed file system, network storage and solid-state storage system.