Deduplication flash file system with PRAM for non-linear editing

Deduplication is essential for efficient nonlinear editing (NLE), as large amounts of duplicated data are caused by NLE. In this paper, a new deduplication file system is designed for an embedded system based on NAND flash memory. In the suggested file system, to reduce computation overhead, duplication caused by NLE operations is predicted considering causality between I/O operations. Furthermore, an efficient management scheme for the shared data among files is proposed in NAND flash memory, including data indexing and garbage collection. The data indexing has distinctive characteristics in that it releases the page-alignment constraint and allows page sharing. The proposed garbage collection efficiently supports shared data in NAND flash memory. With this file system, it is possible to reduce write operations for redundant data and thus use NAND flash memory space efficiently. As a result, garbage collection overhead can be reduced greatly. Moreover, the file system can be widely applied to existing NLE applications, since it is compatible with existing POSIX system calls.