I/O Deduplication: Utilizing Content Similarity to Improve I/O Performance

Duplication of data in storage systems is becoming increasingly common. The authors introduce I/O Deduplication, a storage optimization that utilizes content similarity for improving I/O performance by eliminating I/O operations and reducing the mechanical delays during I/O operations. I/O Deduplication consists of three main techniques: content-based caching, dynamic replica retrieval, and selective duplication. Each of these techniques is motivated by the observations with I/O workload traces obtained from actively-used production storage systems, all of which revealed surprisingly high levels of content similarity for both stored and accessed data.