A Log-based Flash Translation Layer for Large NAND flash memory

Abstract

Flash memory has been widely used in mobile and embedded systems because of non-volatility, low power consumption, shock resistance, lightweight, small size, and fast access speed. However, flash memory has two disadvantages. One is that data cannot be overwritten before erase in advance. The other is that each erasable unit of flash memory has the limitation of possible number of erase operations: generally 100,000 program/erase cycles. To address these problems, the systems have a translation layer and a garbage collection mechanism to provide applications a transparent storage service. It called a flash translation layer (FTL). Recently, mobile and embedded systems use many types of multimedia data. It means that the storage system must have a long life time, fast access speed, and large capacity. To satisfy these requirements, we propose new FTL algorithm called LogFTL (Log-based FTL). We provide the performance result based on our implementation of LogFTL and other FTLs