A simulation analysis of reliability in primary storage deduplication
Min Fu, Patrick P. C. Lee, Dan Feng, Zuoning Chen, Yu Xiao · 2016
Deduplication has been widely used to improve storage efficiency in modern primary and secondary storage systems, yet how deduplication fundamentally affects storage system reliability remains debatable. This paper aims to analyze and compare storage system reliability with and without deduplication in primary workloads using real-world file system snapshots. Specifically, we propose a trace-driven, deduplication-aware simulation framework that analyzes data loss in both chunk and file levels due to sector errors and whole-disk failures. Compared to without deduplication, our analysis shows that deduplication consistently reduces the damage of sector errors due to intra-file redundancy elimination, but potentially increases the damages of whole-disk failures if the highly referenced chunks are not carefully placed on disk. To improve reliability, we examine a deliberate copy technique that stores and repairs first the most referenced chunks in a small dedicated physical area (e.g., 1% of the physical capacity), and demonstrate its effectiveness through our simulation framework.