Lifetime Management of Flash-Based SSDs Using Recovery-Aware Dynamic Throttling
Sungjin Lee, Taejin Kim, Kyungho Kim, Jihong Kim · 2012
NAND flash-based solid-state drives (SSDs) are increas-ingly popular in enterprise server systems because of their advantages over hard disk drives such as higher performance and lower power consumption. How-ever, the limited and unpredictable lifetime of SSDs remains to be a serious obstacle to wider adoption of SSDs in enterprise systems. In this paper, we pro-pose a novel recovery-aware dynamic throttling tech-nique, called READY, which guarantees the SSD life-time required by the enterprise market while exploiting the self-recovery effect of floating-gate transistors. Un-like a static throttling technique, the proposed technique makes throttling decisions dynamically based on the pre-dicted future write demand of a workload so that the required SSD lifetime can be guaranteed with less per-formance degradation. The proposed READY technique also considers the self-recovery effect of floating-gate transistors which improves the endurance of SSDs, en-abling to guarantee the required lifetime with less write throttling. Our experimental results show that the pro-posed READY technique can improve write performance by 4.4x with less variations on the write time over the ex-isting static throttling technique while guaranteeing the required SSD lifetime. 1