Anticipatory I/O Management for Clustered Flash Translation Layer in NAND Flash Memory

다국어 초록 (Multilingual Abstract)

Recently, NAND flash memory has emerged as a next generation storage device because it has several advantages, such as low power consumption, shock resistance, and so on. However, it is necessary to use a flash translation layer (FTL) to intermediate between NAND flash memory and conventional file systems because of the unique hardware characteristics of flash memory. This paper proposes a new clustered FTL (CFTL) that uses clustered hash tables and a two-level software cache technique. The CFTL can anticipate consecutive addresses from the host because the clustered hash table uses the locality of reference in a large address space. It also adaptively switches logical addresses to physical addresses in the flash memory by using block mapping, page mapping, and a two-level software cache technique. Furthermore, anticipatory I/O management using continuity counters and a prefetch scheme enables fast address translation. Experimental results show that the proposed address translation mechanism for CFTL provides better performance in address translation and memory space usage than the well-known NAND FTL (NFTL) and adaptive FTL (AFTL).

참고문헌 (Reference)

1 "Samsung Electronics, “K9K8G08U1A”, Data Sheet of NAND Flash Memory"

2 "Samsung Electronics, “K9F1208U0C”, Data Sheet of NAND Flash Memory"

3 A. Silberschatz, "Operating System Concepts, 7th Edition" John Wiley & Sons, Inc. 315-326, 2005

4 MTD, "Memory Technology Device (MTD) subsystem for Linux"

5 "Intel Corporation, Understanding the Flash Translation Layer (FTL) Specification"

6 "Intel Corporation, Software Concerns of Implementing a Resident Flash Disk"

7 A. Ban, "Flash file system. US patent 5,404,485. Filed March 8, 1993; Issued April 4, 1995; Assigned to M-Systems Flash Disk Pioneer Ltd., Tel Aviv, Israel"

8 A. Ban, "Flash file system optimized for page-mode flash technologies. US patent 5,937,425. Filed October 16, 1997; Issued August 10, 1999; Assigned to M-Systems Flash Disk Pioneer Ltd., Tel Aviv, Israel"

9 S.L. Min, "Current Trends in Flash Memory Technology" 2006

10 "CompactFlash Association, “CompactFlash Specification Revision 4.1,”"

11 C.H. Wu, "An Adaptive Two-Level Management for the Flash Translation Layer in Embedded Systems" 2006

12 J. Kim, "A Space Efficient Flash Translation Layer for CompactFlash Systems" 48 (48): 366-375, 2002

13 M. Talluri, "A New Page Table for 64-bit Address Spaces" 184-200, 1995

14 A. Kawaguchi, "A Flash-Memory Based File System" 1995

15 K.-H. Park, "A Clustered Flash Translation for Mass Storage CompactFlash Systems" 2008