WLVT: A Static Wear-Leveling Algorithm with Variable Threshold

NAND flash memory has been successfully employed in storage system due to its advantages such as performance, resistance, and capacity. NAND flash memory based solid state disk (SSD) has started to replace disk in numerous environments. However, the poor endurance offered by these SSDs continues to be their key shortcoming. To improve SSD endurance, we propose a static wear-leveling algorithm with variable threshold (WLVT). In contrast with traditional algorithm with fixed threshold, WLVT adjusts the value of threshold, so that each block can simultaneously reach the erasure times that the manufacturer gives when life of SSD is over. Therefore, available erasure time of each block will be fully utilized when SSD fails. Experimental results show that the endurance of the SSD is significantly improved.