Presentation
FineRR-ZNS: Enabling Fine-Granularity Read Refreshing for ZNS SSDs
DescriptionZoned namespace (ZNS) SSDs are emerging stor- age devices offering low cost, high performance, and software definability. By adopting host-managed zone-based sequential programming, ZNS SSDs effectively eliminate the space over- head associated with on-board DRAM memory and garbage collection. However, while background read refreshing serves as a background data protection mechanism in conventional block-interface SSDs, the state-of-the-art ZNS SSDs lack read refreshing functionality to guarantee the data reliability. More- over, implementing zone-level read refreshing in ZNS SSDs incurs significant overhead due to the large volume of valid data movements in a zone, leading to degraded I/O performance.
To efficiently enable read refreshing for ZNS SSDs, this paper proposes FineRR-ZNS, a fine-granularity read refreshing mechanism for ZNS SSDs. FineRR-ZNS employs a host-controlled fine- granularity read refreshing scheme that selectively determines block-level read refreshing via metadata remapping. Additionally, a zone reconstruction method is designed to retrieve remapped data forming complete data during zone-level RR. Specially, the remapped data after zone reconstruction are still available and prioritized for read accesses until their respective block needs next RR. Experimental evaluations with RocksDB benchmarks show that FineRR-ZNS significantly enhances read refreshing efficiency and I/O throughput compared to zone-level read refreshing implemented in the state-of-the-art ZenFS file system.
To efficiently enable read refreshing for ZNS SSDs, this paper proposes FineRR-ZNS, a fine-granularity read refreshing mechanism for ZNS SSDs. FineRR-ZNS employs a host-controlled fine- granularity read refreshing scheme that selectively determines block-level read refreshing via metadata remapping. Additionally, a zone reconstruction method is designed to retrieve remapped data forming complete data during zone-level RR. Specially, the remapped data after zone reconstruction are still available and prioritized for read accesses until their respective block needs next RR. Experimental evaluations with RocksDB benchmarks show that FineRR-ZNS significantly enhances read refreshing efficiency and I/O throughput compared to zone-level read refreshing implemented in the state-of-the-art ZenFS file system.
Event Type
Research Manuscript
TimeWednesday, June 2511:30am - 11:45am PDT
Location3008, Level 3