Block recycling schemes and their cost-based optimization in nand flash memory based storage system

Flash memory has many merits such as light weight, shock resistance, and low power consumption, but also has limitations like the erase-before-write property. To overcome such limitations and to use it efficiently as storage media in mobile systems, Flash memory based storage systems require special address mapping software called the FTL (Flash-memory Translation Layer). Like cleaning in Log-structured file system (LFS), the FTL often performs a merge operation for block recycling and its efficiency affects the performance of the storage system. To reduce the block recycling costs in NAND Flash memory based storage, we introduce another block recycling scheme that we call migration. Our cost-models and experimental results show that cost-based selection of merge or migration for each block recycling can decrease block recycling costs and, therefore, improve performance of Flash memory based storage systems. Also, we derive the macroscopic optimal migration/merge sequence minimizing b...

• Type: Conference
• Year: 2007
• Where: EMSOFT
• Authors: Jongmin Lee, Sunghoon Kim, Hunki Kwon, Choulseung Hyun, Seongjun Ahn, Jongmoo Choi, Donghee Lee, Sam H. Noh
• Keywords: Block Recycling, EMSOFT 2007, Flash Memory, Memory Based Storage