存储系统的集中式Cache替换算法  

Central Cache replacement algorithm for storage system

作　　者：罗益辉[1] 谢长生[2] 张成峰[2] 

机构地区：[1]湖北大学数学与计算机科学学院,湖北武汉430062 [2]华中科技大学计算机科学与技术学院,湖北武汉430074

出　　处：《华中科技大学学报（自然科学版）》2006年第11期41-43,共3页Journal of Huazhong University of Science and Technology(Natural Science Edition)

基　　金：国家自然科学基金资助项目(60273073;60303031);国家重大基础研究计划资助项目(2004CB318200)

摘　　要：为了最大限度地优化存储系统的I/O性能,通过对存储系统性能的分析,提出一种Cache替换算法———最小访问时间算法(LAT).该算法为Cache中数据对象定义一个排队函数,该函数不仅与对象的Cache命中率有关,还与对象的设备访问速度有关.按照此函数,Cache替换访问次数少、设备访问时间短的对象,从而使得存储系统的平均I/O时间最短.实验结果表明,随着设备访问速度差的增加,LAT算法的平均I/O性能远远优于LRU和LFU.I/O performance of storage system was analyzed. A Cache replacement algorithm, last access time algorithm, is proposed to obtain the highest I/O performance. The algorithm defined a queue function for Cached objects that relate to objects＇ Cache hit ratios and their access time to storage devices. Based on the queue function, Cache replaces the objects that are accessed least and have least access time to storage devices when Cache requires space to Cache the new objects, which makes the storage system have the least average I/O time. The experiment shows that LAT replacement algorithm has the higher I/O performance than LRU and LFU as the difference of device I/O speeds became greater.

关 键 词：存储系统 Cache替换算法 加速比 数据对象 

分 类 号：TP303[自动化与计算机技术—计算机系统结构]