The Design And Research Of A Wear-Leveling Filesystem For Non-volatile Memory

In recent years, the performance gap between memory and processor grows wider, Memory wall problem is fairly prominent, but the traditional DRAM module seems to reach the limit of integration. Then how to design effective storage architecture to solve the problem of memory wall has became the new challenge we must face. The new type of memory, which is represented by the non-volatile memory, is of concern because of the low power consumption and high integration. But the limited NVRAM storage cell write times is one of the great limitations. In the NVRAM storage system, the main challenge is to protect the storage cell excessive updates. For this reason, this paper designed and implemented a wearleveling file system to solve this problem.Based on the analysis and research of the Ext2 file system, this paper designed and implemented a user level file system based on Fuse framework to solve the problem of wear-leveling in NVRAM. In the file system, updating inode table area and free block area is more frequent, so this paper is mainly aimed at the two area to design different solutions to solve the wear leveling problem. Inode table uses a sliding window strategy to prevent premature wear of the storage cell. A model of queue is used in free block area. Each time the application apply for a free block to allocate the block on the head of the queue, and the release of free blocks join in the queue. Thus the problem of the wear leveling in the free block area is solved.The NVRAM wear leveling file system based on Fuse framework in Linux platform. The file system achieved the basic operation of file system. After testing, the design of file system has completed, and the effect on solving the wear problem and stable running relatively good.