The SBM: A Victim Block Selection Method Based on Min-heap Priority Queues

NAND flash memories are widely utilized in embedded systems. However, these memories limited endurance leads to the reduced reliability of flash storage devices. The NAND flash blocks reclamation policy plays a substantial role in its lifetime degradation. The Scoring Based Method (SBM) aims to address this problem. This paper employs priority queues based on a min-heap structure to enhance the lifetime of NAND flash chips in an SSD. The blocks are ordered in the corresponding min-heap based on the factors which directly affect the lifespan of flash blocks. Experiments were conducted using the SSDsim simulation tool. Moreover, the method is evaluated under both write-intensive and read-intensive workloads. The results demonstrate that the SBM enhances the lifetime by at least 2.5 percent compared to its earlier version, and 39.9 percent compared to the rest of the methods.