R&D: Write Amplification Trade-off Analysis in Hybrid Mapping SSD

IEEE Xplore has published, in 2020 15th IEEE Conference on Industrial Electronics and Applications (ICIEA) proceedings, an article written by Li Wang, Min Zhu, and Chunling Yang, School of Electrical Engineering and Automation, Harbin Institute of Technology, Harbin, China.

Abstract: “Write amplification defines the efficiency of write operation, and it directly affects the Input/Output operations per second (IOPS) and endurance of NAND flash memories. The log-updated write scheme of NAND flash based Solid State Drives will renewal data in different places. Garbage collection will cause extra I/O operations which affects the write amplification factor. Hybrid mapping scheme alleviates the large size of mapping table in page mapping scheme, and the IOPS of storage devices in block mapping scheme, so the write amplification trade-off has great effects on the design of hybrid mapping scheme. In this paper, we propose a model to analysis the write amplification trade-off in hybrid mapping scheme. Moreover, we redesign the greedy garbage collection and measure the performance differences between two algorithms in hybrid mapping scheme. Finally, we evaluate the design of write amplification trade-off based hybrid mapping Solid State Drives, and the algorithms proposed in this paper can resuce the write amplification factor and maintain the endurance at a high level.“