Controlling energy usage in data centers, and storage in particular, continues to rise in importance. Many systems and models have examined energy efficiency through intelligent spin-down of disks and novel data layouts, yet little work has been done to examine how power usage over the course of months to years is impacted by the characteristics of the storage devices chosen for use. Longterm power usage is particularly important for archival storage systems, since it is a large contributor to overall system cost. In this work, we begin exploring the impact that broad policies (e.g. utilize high-bandwidth devices first) have upon the power efficiency of a disk based archival storage system of heterogeneous devices over the course of a year. Using a discrete event simulator, we found that even simple heuristic policies for allocating space can have significant impact on the power usage of a system. We show that our system growth policies can cause power usage to vary from 10% higher to ...
Ian F. Adams, Ethan L. Miller, Mark W. Storer