DEDIS: Distributed Exact Deduplication for Primary Storage

Deduplication is now widely accepted as an efficient technique for reducing storage costs at the expense of some processing overhead, being increasingly sought in primary storage systems [7, 8] and cloud comput-ing infrastructures holding Virtual Machine (VM) vol-umes [2, 1, 5]. Besides a large number of duplicates that can be found across static VM images [3], dynamic gen-eral purpose data from VM volumes allows space sav-ings from 58 % up to 80 % if deduplicated in a cluster-wide fashion [1, 4]. However, some of these volumes persist latency sensitive data which limits the overhead that can be incurred in I/O operations. Therefore, this problem must be addressed by a cluster-wide distributed deduplication system for such primary storage volumes. Although considerable space savings are obtainable