Efficient Wear-leveling Scheme for Flash Memory File System

Abstract

Flash memory has a restriction that a block should be erased prior to data write. Moreover, there is a limit on the erase count of each block. If data writes are concentrated on some blocks, the blocks are worn out earlier than other blocks and then the lifetime of a flash memory is shortened. Therefore, flash memory file system should provide an efficient wear-leveling scheme that improves robustness of the storage by making all blocks used in an even frequency. Previous wear-leveling schemes require large computation overheads and erase count maintenance costs. In this paper, we propose an efficient wear-leveling scheme for a flash memory file system that is simple and effectively levels erase counts regardless of the file access pattern. The wear-leveling capability is evaluated through experiment and compared with the existing flash memory file system.