2016 USENIX Annual Technical Conference (USENIX ATC '16)

Storage systems are designed and optimized relying on wisdom derived from analysis studies of file-system and block-level workloads. However, while SSDs are becoming a dominant building block in many storage systems, their design continues to build on knowledge derived from analysis targeted at hard disk optimization. Though still valuable, it does not cover important aspects relevant for SSD performance. In a sense, we are “searching under the streetlight”, possibly missing important opportunities for optimizing storage system design.

We present the first I/O workload analysis designed with SSDs in mind. We characterize traces from four repositories and examine their ‘temperature’ ranges, sensitivity to page size, and ‘logical locality’. Our initial results reveal nontrivial aspects that can significantly influence the design and performance of SSD-based systems.