面向Linux非逻辑卷块设备的快照系统  

Snapshot System for Linux Non-logical Volume Block Devices

作　　者：宋东平 胡晓勤 谢俊峰 钱禹航 SONG Dong-Ping;HU Xiao-Qin;XIE Jun-Feng;QIAN Yu-Hang(School of Cyber Science and Engineering,Sichuan University,Chengdu 610207,China;Chengdu Vinchin Technology Co.Ltd.,Chengdu 610041,China)

机构地区：[1]四川大学网络空间安全学院,成都610207 [2]成都云祺科技有限公司,成都610041

出　　处：《计算机系统应用》2022年第5期131-136,共6页Computer Systems & Applications

基　　金：国家自然科学基金(61872255)。

摘　　要：为满足Linux操作系统下非逻辑卷块设备需要在不添加额外块设备存储数据的场景下创建临时快照的需求,设计实现了一种针对Linux非逻辑卷块设备的快照系统.系统基于写时拷贝(COW),分为应用层和内核层中的通用块层两部分.应用层部分对用户的快照创建或删除命令分析并传递到通用块层部分,通用块层部分创建或删除快照设备,在快照创建后截获快照源设备的通用块层I/O(bio)请求并做COW.实验结果表明系统能正确创建快照,其最佳拷贝块大小为4 MB,对于快照源设备的新增写性能最低影响低于10%.Given that non-logical volume block devices under the Linux operating system need to create temporary snapshots without additional block devices being added to store data,this study designs and implements a snapshot system for Linux non-logical volume block devices.The system has an application layer and a generic block layer of the inner nuclear layer and is based on copy-on-write(COW).The application layer analyzes the user’s creation or deletion commands and transmits them to the generic block layer.The general block layer creates or deletes the snapshot devices and intercepts the general block layer I/O(bio)request of the source device and performs COW after the snapshot is created.Experimental results show that the system can create snapshots correctly.The optimal copy block size is 4 MB.The minimum impact on the write performance of the source device is less than 10%.

关 键 词：非逻辑卷 块设备 快照 写时拷贝 通用块层 LINUX 

分 类 号：TP316.81[自动化与计算机技术—计算机软件与理论] TP311.13[自动化与计算机技术—计算机科学与技术]