Exploiting In-Memory and On-Disk Redundancy to Conserve Energy in Storage Systems

Abstract--Today's storage systems place an imperative demand on energy efficiency. A storage system often places single-rotationrate disks into standby mode by stopping them from spinning to conserve energy when the workload is not heavy. The major obstacle of this method is a high spin-up cost introduced by passively waking up the standby disk to service requests. In this paper, we propose a redundancy-based hierarchical I/O cache architecture called RIMAC to solve the problem. The idea of RIMAC is to enable data on the standby disk(s) to be recovered by accessing a two-level I/O cache and/or active disks if needed. In parity-based redundant disk arrays, RIMAC exploits parity redundancy to dynamically XOR-reconstruct the data being accessed toward standby disk(s) at both the cache and disk levels. By avoiding passive spin-ups, RIMAC can significantly improve both energy efficiency and performance. In RIMAC, we developed 1) two power-aware read request transformation schemes calle...

• Type: Journal
• Year: 2008
• Where: TC
• Authors: Jun Wang, Xiaoyu Yao, Huijun Zhu
• Keywords: Cache, Energy Efficiency, Information Technology, Standby Disk, TC 2008