Re-aligning across-page requests for flash-based solid-state drives

Zhigang Cai (1) , Chengyong Tang (1) , Minjun Li (1) , François Trahay (2, 3, 4) , Jun Li (1) , Zhibing Sha (1) , Jiaojiao Wu (1) , Fan Yang (1) , Jianwei Liao (1)

1 Chongqing University [Chongqing]
2 IP Paris - Institut Polytechnique de Paris
3 TSP - INF - Département Informatique
4 Benagil-Samovar - Efficient and safe distributed systems

In flash-based solid-state drives (SSDs), certain small unaligned I/O requests span two logical pages though their size is not larger than the basic write/read unit of SSDs (i.e. an SSD page), and we term them as across-page requests. Servicing such across-page requests triggers two separated I/O operations on different SSD pages, and thus impacts the I/O performance and the endurance of SSDs. For mitigating negative effects caused by across-page requests, this paper proposes a novel flash translation layer (FTL) scheme for SSDs to separately realign such requests via remapping them onto a single SSD page. Consequently, both read and write requests on the across-page data can be completed with one page-level I/O operation. Through a series of experiments based on the selected disk traces of real-world applications, we demonstrate that the proposed realigning method at FTL of SSD devices, can noticeably reduce the I/O latency by between 4.6% and 11.6%, and the erase number (i.e. the indicator of SSD endurance) by between 6.4% and 19.11%, compared to state-of-the-art methods. CCS Concepts: • Computer systems organization → Embedded software.

Mots clés: Solid-state Drives (SSDs); Unaligned I/Os; Acrosspage Remapping; I/O Performance

Domaines: Informatique [cs]

Zhigang Cai, Chengyong Tang, Minjun Li, François Trahay, Jun Li, et al.. Re-aligning across-page requests for flash-based solid-state drives. The 52nd International Conference on Parallel Processing (ICPP), Aug 2023, Salt Lake City, United States. pp.736-745, ⟨10.1145/3605573.3605652⟩. ⟨hal-04155595⟩