An adaptive block-set based management for large-scale flash memory

With rapid increase of the capacity of flash-memory storage systems, it becomes critical to provide efficient management for large-scale flash-memory. Compared with FTL (Flash Translation Layer), NFTL (NAND Flash Translation Layer) provides less main-memory space requirements for large-scale flash memory. However, because each replacement block is exclusively used by a logical block, NFTL exhibits poor space utilization of flash memory. In this paper, we present an adaptive block-set based flash memory management. The presented scheme adopts shared and exclusive replacement blocks, and allocates replacement blocks according to the update loads of logical blocks. The experimental results show that the presented scheme yields a better performance in garbage collection than NFTL and FAST (fully associative sector translation), keeping space utilization of flash memory at high level.