面向非易失性内存文件系统的NVM模拟与验证方法  

Method for Simulating and Verifying NVM-based In-memory File Systems

作　　者：王鑫鑫 诸葛晴凤 吴林 WANG Xin-xin;ZHUGE Qing-feng;WU Lin(College of Computer Science,Chongqing University,Chongqing 400044,China;Shool of Computer Science and Software Engineering,East China Normal University,Shanghai 200062,China)

机构地区：[1]重庆大学计算机学院,重庆400044 [2]华东师范大学计算机科学与软件工程学院,上海200062

出　　处：《计算机科学》2020年第9期74-80,共7页Computer Science

基　　金：国家高技术研究发展计划(863计划)(2015AA015304);国家自然科学基金(61472052)。

摘　　要：现有非易失性内存文件系统都以DRAM模拟非易失性内存(Non-Volatile Memory,NVM)进行测试,而没有充分考虑两者间的写时延和写磨损特性差异,使得测试结果无法准确反映文件系统在NVM物理设备上的写性能以及对NVM造成的磨损情况。现有NVM模拟器准确度不高,且仿真接口不完备,无法满足内存文件系统对NVM的仿真需求。对此,提出一种面向非易失性内存文件系统的NVM模拟与验证方法。首先,结合非易失性内存文件系统本身的数据读写特性,提出内存文件系统中NVM写时延的模拟方案;其次,跟踪内存文件系统对NVM的读写操作,以验证文件系统对NVM物理设备的写磨损分布情况。选取多个典型内存文件系统实现上述方法。实验结果表明,提出的写时延模拟方法能够将写时延的模拟误差平均降低65%,写磨损验证方法能够较准确地反映内存文件系统对不同粒度NVM页面的磨损分布情况。Most existing NVM-based file systems conduct experiments by simulating NVM with DRAM.However,they ignore the differences between NVM and DRAM,and make it impossible to accurately reflect the performance and wear distribution of file systems on NVM devices.The accuracy and interfaces of existing NVM emulators are not sufficient to support the simulation requirements of NVM-based file systems.This paper proposes a method for simulating NVM write latency and verifying wear distribution of NVM-based file systems.The accuracy of latency simulation is improved by injecting software-created delay according to the I/O characteristics of file system.To depict the wear distribution of NVM physical devices caused by the NVM-based file system,every update operation to NVM page is tracked.Experimental results show that the proposed method can reduce the error rate of write latency simulation by 65%on average,while accurately reflect the wear distribution of NVM.

关 键 词：非易失性存储器 内存文件系统 写时延 磨损均衡 

分 类 号：TP316.89[自动化与计算机技术—计算机软件与理论]