QMD: exploiting flash for energy efficient disk arrays

Abstract

Energy consumption for computing devices in general and for data centers in particular is receiving increasingly high attention, both because of the increasing ubiquity of computing and also because of increasing energy prices. In this work, we propose QMD (Quasi Mirrored Disks) that exploit flash as a write buffer to complement RAID systems consisting of hard disks. QMD along with partial on-line mirrors, are a first step towards energy proportionality which is seen as the "holy grail" of energy-efficient system design. QMD exhibits significant energy savings of up 31%, as per our evaluation study using real workloads.