ETRI Journal
- Volume 30 Issue 6
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- Pages.790-798
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- 2008
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- 1225-6463(pISSN)
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- 2233-7326(eISSN)
Anticipatory I/O Management for Clustered Flash Translation Layer in NAND Flash Memory
- Park, Kwang-Hee (Department of Electronic Engineering, Inha University) ;
- Yang, Jun-Sik (Department of Electronic Engineering, Inha University) ;
- Chang, Joon-Hyuk (Department of Electronic Engineering, Inha University) ;
- Kim, Deok-Hwan (Department of Electronic Engineering, Inha University)
- Received : 2008.03.05
- Accepted : 2008.10.08
- Published : 2008.12.31
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).