LAZA: ZNS SSD의 수명 연장을 위한 라이프타임 기반 Zone 할당 기법

초록

Traditional SSDs face considerable significant garbage collection (GC) overhead due toout-of-place updates.Zoned Namespace SSDs (ZNS SSDs) have been developed to mitigate this issue,offering reliable operation and enhanced write performance.RocksDB, a popular LSM-tree basedkey-value store, can take advantage of ZNS SSDs through the ZenFS filesystem.To maximize writethroughput, RocksDB employs multiple compaction threads; however, the zone allocation strategy inZenFS results in high write amplification and frequent Zone Finish operations in multi-compactionscenarios.These factors accelerate the wear of ZNS SSDs and shorten their effective lifespan.In thispaper, we introduce Lifetime-Aware Zone Allocation (LAZA), a zone allocation scheme that takes intoaccount the lifetime ratios of files within zones.LAZA eliminates the need for additional Zone Finishoperations during zone allocation, significantly reducing GC-induced write amplification.Ourrxperimental results show that LAZA reduces the number of active zones and zone reset operationsby 10% and 14%, respectively, compared to ZenFS.These enhancements effectively prolong thelifespan of ZNS SSDs while preserving high write performance.

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