Adaptive multi-phased wear leveling method for SSD lifetime enhancement

In NAND flash-based Solid-State Drives (SSDs), the limited endurance of flash memory makes Wear Leveling (WL) a critical technique for extending the lifetime and improving reliability. However, existing WL methods rely on fixed thresholds or a single dynamic threshold applied uniformly throughout SSD lifetime, which fails to adapt to dynamic wear conditions, such as uneven block wear and workload-induced variations in I/O intensity. This limitation can result in excessive data migration and performance degradation. This paper proposes an Adaptive Multi-Phased Wear Leveling method (called AMPWL) to extend SSD lifetime and improve system performance. Firstly, AMPWL divides the SSD lifetime into three distinct phases to better capture its wear characteristics. Secondly, phase-specific dynamic thresholds are designed to adaptively trigger wear leveling operations. Thirdly, a scoring mechanism is introduced to enhance wear leveling efficiency. Experimental results demonstrate that AMPWL significantly outperforms existing wear leveling methods in extending SSD lifetime and improving I/O performance.