R-Dedup: Content Aware Redundancy Management for SSD-based RAID Systems

While high density SSDs are increasingly adopted in enterprise computing environment, it remains a challenge to meet the high performance and reliability demands of server applications as well as the demands for longer system lifetime and high space utilization in such environment. Existing schemes often address these issues separately. In particular, deduplication schemes improve write performance and SSD lifetime while SSD-based RAID designs improve reliability and read performance. Naively integration of deduplication and RAID results in suboptimal designs. In this paper, we propose R-Dedup, a content-aware redundancy management scheme for SSD-based RAID storage. By combining deduplication with replication, R-Dedup evaluates system performance, reliability, endurance and space utilization, and dynamically manages replicas to achieve better tradeoff. Our experimental results show that R-Dedup achieves 18% and 20% improvements on read and write performance, respectively, and extends SSD lifetime by 20% with no reliability compromise.(1)