S-Space College of Engineering/Engineering Practice School (공과대학/대학원) Dept. of Computer Science and Engineering (컴퓨터공학부) Theses (Master's Degree_컴퓨터공학부)
SlimFTL: a Small and Fast Page-level FTL using Hash Functions
- Issue Date
- 서울대학교 대학원
- hash-based mapping; page-level mapping; garbage collection cost; flash translation layer; solid-state disks; 해시기반 맵핑; 페이지 레밸 맵핑; 가비지 컬렉션 비용; 플래시 변환 계층; SSD
- 학위논문 (석사) -- 서울대학교 대학원 : 공과대학 컴퓨터공학부, 2020. 8. 김지홍.
- As the capacity of an SSD increases, the amount of DRAM for managing the SSD increases proportionally. Since the DRAM cost directly affects the overall SSD price, it is important to minimize the DRAM size without degrading the SSD performance. In this paper, we propose a novel hash-based FTL mapping technique, SlimFTL, that meets this goal. SlimFTL overcomes the GC inefficiency problem of an existing hash-based FTL in two directions. By employing an efficient indirection layer between the logical page and its hashed physical block, SlimFTL reduces the block copy overhead during GC. SlimFTL exploits the spatial sequentiality among successive writes so that sequential writes can be mapped to the same physical block, which significantly reduces the number of valid copies during GC. Experimental results show that SlimFTL can achieve the same performance level of a page-level mapping scheme with only 44% of the DRAM capacity.