【摘要】 磁盘及其冷却系统是现代存储系统中能耗的主体,已有的节能研究主要面向以随机数据访问为主的存储系统,对于广泛存在的以顺序数据访问为主的存储系统,如视频监控、虚拟磁带库(VTL)、连续数据保护(CDP)等,针对该类系统固有访问模式的节能研究较少.为此,提出了适用于顺序数据访问的节能磁盘阵列S-RAID 5,采用局部并行策略:阵列中的存储区被分成若干组,组内采用并行访问模式,分组有利于调度部分磁盘运行而其余磁盘待机,组内并行用以提供性能保证.在S-RAID 5磁盘阵列中运行磁盘调度算法,辅以合适的Cache策略来过滤少量的随机访问,S-RAID 5可获得显著的节能效果.在32路D1标准的视频监控模拟实验中,在满足性能需求、单盘容错的条件下,24小时功耗测量实验表明:S-RAID 5的功耗为节能磁盘阵列Hibernator功耗的59%,eRAID功耗的23%,PARAID、GRAID功耗的21%左右.更多还原

【Abstract】 In modern-day storage systems,disk arrays and their cooling systems consume a major portion of total system power consumption.The existing research work on energy conservation mainly concentrates on optimizing the storage systems for random access-based applications.However,for the widely-used storage systems for sequential access-based applications,such as video surveillance,continuous data protection(CDP),virtual tape library(VTL),few schemes are proposed to gain better energy conservation according to their inherent characteristics with I/O performance guarantee so far.To this end,S-RAID 5,an energy-saving RAID system,is proposed for sequential access-based applications.In S-RAID 5,a local-parallelism strategy is employed: the entire storage area of the array is partitioned into different groups,and in each group a parallel data access scheme is adopted.Data grouping makes it possible to keep only a portion of disks active while keeping the rest standby.On the other hand,the intra-group parallelism is used to provide the performance guarantee.With an appropriate caching strategy to filter out a small amount of random accesses,S-RAID 5 can achieve prominent energy saving.In a simulation experiment of 32-channel video surveillance with D1 resolution standard,the measurement results of 24-hour power consumption show that the power consumption of S-RAID 5 is 59%,23%,21%,and 21% of those of Hibernator,eRAID,PARAID,and GRAID,respectively,while meeting the I/O performance and single-disk fault tolerance.更多还原