Adaptive Mapping Information Management Scheme for High Performance Large Sale Flash Memory Storages

NAND flash memory has been widely used as a storage medium in mobile devices, PCs, and workstations due to its advantages such as low power consumption, high performance, and random accessability compared to a hard disk drive. However, NAND flash cannot support in-place update so that it is mandatory to erase the entire block before overwriting the corresponding page. In order to overcome this drawback, flash storages need a software support, named Flash Translation Layer. However, as the high performance mass NAND flash memory is getting widely used, the size of mapping tables is increasing more than the limited DRAM size. In this paper, we propose an adaptive mapping information caching algorithm based on page mapping to solve this DRAM space shortage problem. Our algorithm uses a mapping information caching scheme which minimize the flash memory access frequency based on the analysis of several workloads. The experimental results show that the proposed algorithm can increase the performance by up to 70% comparing with the previous mapping information caching algorithm.