An Adaptation Layer for Hardware Restrictions of Quadruple-Level Cell Flash Memories

Abstract

In recent years, major flash memory vendors have produced SSDs and fusion memories as substitution for hard disks. However, there has been a lack of studies on access restriction of QLC flash memory, since most researches have targeted small capacity flash memory. As a solution, we propose to implement an adaptation layer between the file system and FTL (Flash Translation Layer). Instead of immediately writing data given from file system to flash memory, the adaptation layer gathers and adjusts data in the unit of a page, and separates random data from sequential data. By implementing the adaptation layer, previous FTL algorithms can be fully applied on the QLC flash memory. According to our experiment, the adaptation layer forms smaller number of pages than the current data gathering algorithm.