대용량 플래시 메모리 드라이브를 위한 효율적인 플래시 변환계층 캐시 관리 방안

다국어 초록 (Multilingual Abstract)

Nowadays, large size flash memory drives with more than a couple of hundreds of gigabytes are common. This paper presents an efficient cache management scheme of flash translation layer, called TPC-FTL, for large size flash memory drives. Since flash drives of large size usually contain large size RAM, we can enhance the performance of page mapping cache by using more RAM for the cache. But if the size exceeds a threshold, the existing schemes are impractical for real devices, because the time for cache manipulation becomes too long. TPC-FTL manages the cache in translation page unit, not in logical page number unit used in existing schemes. Since a translation page covers a large number of logical page numbers (for example, 512 for 2KB size page), the number of cache elements can be reduced up to a practical level. A performance evaluation shows that average response time, an important performance measure, is better than existing schemes via the effect of utilizing spacial locality in addition to temporal locality.

참고문헌 (Reference)

1 "Yet another flash file system"

2 "Storage Traces of UMass Trace Repository"

3 Samsung Electronics, "Samsung SSD 850 PRO Data Sheet, Rev.2.0"

4 J. Boukhobza, "MaCACH: An Adaptive Cache-Aware Hybrid FTL Mapping Scheme Using Feedback Control for Effieient Page-Mapped Space Management" Elsevier 157-171, 2015

5 A. B. Bityutskiy, "JFFS3 design issues"

6 C. Lee, "F2FS: A New File System for Flash Storage" 273-286, 2015

7 A. Gupta, "DFTL: a Flash Translation Layer Employing Demand-based Selective Caching of Page-level Address Mappings" 2009

8 E. Goossaert, "Coding for SSDs – Part 2: Architecture of an SSD and Benchmarking"

9 D. Park, "CFTL: An Adaptive Hybrid Flash Translation Layer with Efficient Caching Strategies" 1-15, 2011

10 C. Wang, "ADAPT: efficient workload-sensitive flash management based on adaptation, prediction and aggregation" 2012

11 S. Lee, "A log buffer based flash translation layer using fully associative sector translation" 6 (6): 1-27, 2007