,A reliable and energy-efficient storage system with erasure coding cache

• 作 者: Ji-guang WAN Da-ping LI Xiao-yang QU Chao YIN Jun WANG Chang-sheng XIE
• 机 构: Wuhan National Laboratory for Optoelectronics, Department of Computer Science and Technology, Huazho
• 出 处: 信息与电子工程前沿（英文版）
• 发表日期: 2017年9期
• 关键词: Reliability Energy-efficient Storage system Erasure coding Cache management

In mode energy-saving replication storage systems, a primary group of disks is always powered up to serve incoming requests while other disks are often spun down to save energy during slack periods. However, since new writes cannot be immediately synchronized into all disks, system reliability is degraded. In this paper, we develop a high-reliability and energy-efficient replication storage system, named RERAID, based on RAID10. RERAID employs part of the free space in the primary disk group and uses erasure coding to construct a code cache at the front end to absorb new writes. Since code cache supports failure recovery of two or more disks by using erasure coding, RERAID guarantees a reliability comparable with that of the RAID10 storage system. In addition, we develop an algorithm, called erasure coding write (ECW), to buffer many small random writes into a few large writes, which are then written to the code cache in a parallel fashion sequentially to improve the write performance. Experimental results show that RERAID signifi cantly improves write performance and saves more energy than existing solutions.