E-mail: yimodu@gmail.com; Yi-Mo Du got his B.S. degree of computer science and technology from Jilin University, China, in 2008. He achieved his M.S. degree of computer science and technology from National University of Defense Technology (NUDT), China, in 2010. Now he is pursuing his Ph.D. degree in NUDT. His current research interests include distributed file system,network storage and solid state storage system. Corresponding Author {nongxiao }@nudt.edu.cn; Nong Xiao received the B.S., M.S. and Ph.D. degrees of com- puter science from NUDT, China. Now he is a professor in the State Key Laboratory of High Performance Computing, NUDT. His current research interests include large-scale storage system, network computing, and computer architecture. { liufang}@nudt.edu.cn; Fang Liu received the B.S. and Ph.D. degrees of computer science from NUDT, China, in 1999 and 2005 respectively. Now she is an associate professor in the State Key Laboratory of High Performance Computing, NUDT. Her current research interests include distributed file system, network storage and solid-state storage system. chenzhiguanghit@gmail.com Zhi-Guang Chen got his B.S. degree of computer science and tech- nology from Harbin Institute of technology in 2007. He achieved his M.S. degree of computer science and technology from NUDT in 2009. Now he is pursuing his doctor degree in NUDT. His current research interests include distributed file system, net-work storage and solid state storage system.