TY  - JOUR
T1  - Managing DISCARD Commands in F2FS File System for Improving Lifespan and Performance of SSD Devices
AU  - Kim, Jinwoong 
AU  - Kang, Donghyun 
AU  - Eom, Young Ik 
JO  - Journal of KIISE, JOK
PY  - 2024
DA  - 2024/1/14
DO  - 10.5626/JOK.2024.51.8.669
KW  - file system
KW  - storage system
KW  - F2FS
KW  - SSD
KW  - DISCARD
KW  - segment allocation
AB  - The DISCARD command is an interface that helps improve the lifespan and performance of SSDs by informing the SSD devices about invalid file system blocks. However, in the F2FS file system, the DISCARD command is only sent to the SSD during idle time, which limits the potential for improving lifespan and performance. In this paper, we propose an EPD scheme to efficiently transfer DISCARD commands during short idle times, as well as a seg-ment allocation scheme called PSA, which replaces DISCARD commands with overwrite commands. To evaluate the effectiveness of these proposed schemes, we conducted several experiments using various workloads to verify the lifespan and performance of real SSD devices. The results showed that the proposed schemes can improve the write amplification factor (WAF) by up to 40% and throughput by up to 160%, when compared to the traditional F2FS file system.