EBA-GC: An Efficient Block-Associativity-Aware Garbage Collection Scheme for Flash-Memory-Based File Systems

초록

NAND flash memory is now commonly used for data storage in mobile, personal and even enterprise computer systems, as this type of memory has many advantages, such as low-power consumption, shock-resistance, non-volatility, and a small form factor. In NAND flash-memory-based file systems, a garbage collection process is required due to the erase-before-write constraint of NAND flash memory. The efficiency of garbage collection is an important issue because it affects the overall I/O performance. In this paper, we propose an efficient garbage collection scheme for file systems based on NAND flash memory. Our garbage collection scheme can be combined with existing hybrid flash translation layers of file systems. The proposed scheme considers the block associativity of the blocks when selecting a victim block. Our trace-driven simulation results show that the proposed block associativity aware garbage collection scheme reduces the number of time-consuming block erasures. It also reduces the average and maximum response times.