AAGC: An efficient associativity-aware garbage collection scheme for hybrid FTLs

Abstract

NAND ash memory has many advantages such as low-power consumption, shock-resistance, and non-volatility. For these reasons, NAND ash memory is used for data storage purposes in mobile, personal and even enterprise computer systems. When we use NAND ash memory as a means of data storage, it requires a garbage collection procedure due to its erase-before-write characteristic. The efficiency of this garbage collection is an important issue because it affects the performance of the NAND ash memory. In this paper, we propose an efficient garbage collection scheme that can be combined with previous hybrid FTLs. Our garbage collection scheme considers the associativity of the blocks when selecting a victim block. The proposed scheme effectively reduces the number of time-consuming block erasures. Our trace-driven simulation results show that the proposed garbage collection scheme can reduce the number of block erasures by as much as 14%. It can also reduce the average response time and maximum response time by nearly 10% and 70%, respectively. © 2012 ACM.