R&D: De-Dupe-for-Speed, Storing Duplications in Fast Programming Mode for Enhanced Read Performance
Evaluation of 6 real-world traces showed that DFS improved read latency by 16% on average and up to 34%, also enhanced write latency by 64% on average and up to 82%.
This is a Press Release edited by StorageNewsletter.com on September 13, 2022 at 2:01 pmACM Digital Library has published, in SYSTOR ’22: Proceedings of the 15th ACM International Conference on Systems and Storage, an article written by Jaeyong Bae, Jaehyung Park, Sungkyunkwan University, Suwon, Republic of Korea, Yuhun Jun, Samsung Electronics Co., Ltd., Suwon, Republic of Korea, and Euiseong Seo, Sungkyunkwan University, Suwon, Republic of Korea.
Abstract: “Storage deduplication improves write latency, increases available space, and reduces the wear of storage media by eliminating redundant writes. The flash translation layer (FTL) of a flash solid state disk (SSD) easily enables deduplication in an SSD through the simple mapping of duplicated logical pages to the same physical page. Therefore, a few deduplicating FTLs have been proposed. However, the deduplication of partially duplicated files breaks the sequentiality of data storage at the flash page level, resulting in a significant degradation of the read performance. Although increasing available storage space, reducing flash write, and extending lifespan are barely perceptible to users, extended read latency is critical to user-perceived performance. In this paper, we propose a novel deduplication FTL called Dedup-for-Speed (DFS). The DFS FTL trades surplus capacity gained through inline deduplication for improved read performance by storing duplicated pages in fast flash modes, such as the pseudo-single-level-cell(pSLC) mode. The flash mode of a page is determined by its degree of deduplications. Duplicate pages are migrated to fast flash blocks during idle intervals to minimize interference with host-issued operations. Contrary to conventional deduplication schemes, DFS improves the read performance while maintaining the aforementioned benefits of deduplication. Our evaluation of six real-world traces showed that DFS improved the read latency by 16% on average and up to 34%. It also enhanced the write latency by 64% on average and up to 82%.“