A Novel NAND Flash FTL for Mass Data Storage Devices Based on Hybrid Address Translation

摘要

This paper presents a new NAND Flash Translation Layer, called MH-FTL, for Mass data storage devices based on Hybrid address translation, which improved the performance of mass data storage markedly. Firstly, MH-FTL decreases memory space of the address mapping table greatly by three levels address mapping method, including block group level address translation (BGAT), block level address translation (BAT) and page level address translation (PAT). Secondly, it makes the storage devices always working at its best performance through pipeline block group address mapping technology and parallel block group address mapping technology for BGAT and pipeline block address translation for BAT, all of those methods take the integrating way of multi-Flash within mass data storage devices into account. Thirdly, it uses non-associate page address translation with double threshold values to guarantee the small data write performance. Compared with the existing PAT, BAT and HAT FTL, MH-FTL's write amplification is almost the same as PAT and HAT, but far below to BAT, the effective write speed is the best of all. Under the performance estimate condition of this paper, MH-FTL's write speed is more than ten times fast of PAT, BAT, and HAT at most. For large data storage, the memory space occupation of address mapping table is one-sixteenth of BAT and HAT, and the small data write performance is not decreased as well.