Paper Info
Title
Realwear: Improving Performance And Lifetime Of Ssds Using A Nand Aging Marker
Abstract
Although NAND flash memory has revolutionized how we manage data in modern digital systems, significant improvements are needed in flash-based storage systems to meet the requirements of emerging data-intensive applications. In this paper, we address the problem of NAND aging markers that represent the wearing degree of NAND cells. Since all flash operations are affected by the wearing status of NAND cells, an accurate NAND aging marker is critical to develop flash optimization techniques. From our evaluation study, we first show that the existing P/E cycle-based aging marker (PeWear) is inadequate to estimate the actual aging status of NAND blocks, thus losing opportunities for further optimizations. To overcome the limitations of PeWear, we propose a new NAND aging marker, RealWear, based on extensive characterization studies using real 3D TLC flash chips. By considering multiple variables that can affect the NAND cell wear, RealWear can accurately indicate the actual wear status of NAND blocks during run time. Using three case studies, we demonstrate that RealWear is effective in enhancing the lifetime and performance of a flash storage system. Our experimental results showed that RealWear can extend the lifetime of individual NAND blocks by 63% and can reduce the GC overhead by 21%. Furthermore, RealWear significantly mitigates read latency fluctuations, guaranteeing that the read latency can be bounded with at most 2 read retry operations. (c) 2020 Elsevier B.V. All rights reserved.
Year
DOI
Venue
2021
10.1016/j.peva.2020.102153
PERFORMANCE EVALUATION
Keywords
DocType
Volume
NAND aging marker, Flash memory, SSD, Storage, Performance, Reliability
Journal
145
ISSN
Citations 
PageRank 
0166-5316
0
0.34
References 
Authors
0
7
Name
Order
Citations
PageRank
Myung-Suk Kim16910.51
Myoungjun Chun262.18
Duwon Hong332.48
Yoona Kim471.85
Geonhee Cho500.68
Dusol Lee600.68
Jihong Kim71336104.37