跨数据中心虚拟机在线迁移研究

发布时间：2018-03-14 13:22

本文选题：数据中心　切入点：虚拟机　出处：《西北师范大学》2013年硕士论文　论文类型：学位论文

【摘要】：虚拟化技术被用于数据中心的资源管理。虚拟机在线迁移机制，能够使虚拟机和应用在不同的硬件资源之间移动，使数据中心的管理机制具有资源共享，资源调度，容灾备份，动态整合等能力，提高整个数据中心服务质量，安全性以及资源的利用率。虚拟机在线迁移机制只能局限于局域网中，不同的虚拟机通过局域网共享集中存储的虚拟机镜像时，由于局域网中带宽大，延迟低，能够保证提供给用户的服务质量。在跨数据中心环境中，不仅需要管理一个数据中心内的资源，而且面临统一管理地理位置上广泛分布的多个数据中心的问题。由于数据中心之间网络带宽低，延迟高特征，在数据中心之间共享镜像文件时，虚拟机需要进行远程I/O访问虚拟机镜像，降低运行效率。因此，设计虚拟专用通道连接多个的数据中心，打破多个数据中心之间的边界，利用其完善的安全技术保证数据中心在互联之后的安全性。基于XEN虚拟机迁移机制，设计了带镜像文件的虚拟机在线迁移，利用Qcow（Qemu copy on write）机制的镜像文件具有的强扩展能力和模板镜像的共享机制，虚拟机在迁移时不发送模板镜像，不需要传送GB级数量的镜像文件。在内存迭代开始之前将Qcow文件的全部内容发送到目的节点对应的文件系统中，内存迭代过程中实时监控虚拟机对Qcow文件的写操作，记录脏块，每轮迭代结束后将内存脏页和脏块记录一起发送到目的节点，目的节点接收数据后，调用内存映射和磁盘驱动将数据映射到对应的位置。并对内存迭代过程实施了优化，减少虚拟机在重负载时迭代产生的脏页，计算每条监控记录中文件内容的Hash值，保存在缓存中，相同Hash值的文件只发送一次，，减少传送的数据量。本文实现的跨数据中心的虚拟机在线迁移机制，在保证业务正常运行的前提下在数据中心之间实现虚拟机在线迁移，为数据中心之间的资源管理提供基础方法。最好状态下总体迁移时间在120s以内，宕机时间在5ms以内。但决定迁移总时间的关键因素是Qcow镜像文件的大小，随文件的增大而成比例增大。
[Abstract]:Virtualization technology is used in resource management of data center. Virtual machine online migration mechanism can make virtual machine and application move between different hardware resources, make the management mechanism of data center have resource sharing, resource scheduling, disaster recovery backup. Dynamic integration and other capabilities to improve the quality of service, security and resource utilization of the entire data center. Virtual machine online migration mechanism can only be confined to the local area network, different virtual machines share the centralized storage of virtual machine images through the local area network. Because of the large bandwidth and low delay in LAN, the quality of service provided to users can be guaranteed. In the cross-data center environment, not only the resources in one data center need to be managed, but also the problem of unified management of many widely distributed data centers in geographical location. When sharing mirroring files between data centers, virtual machines need remote I / O access to virtual machine images to reduce running efficiency. Therefore, virtual dedicated channels are designed to connect multiple data centers and break the boundary between multiple data centers. Using its perfect security technology to ensure the security of the data center after interconnection. Based on the migration mechanism of XEN virtual machine, the virtual machine online migration with mirror file is designed. The mirror file of Qcow(Qemu copy on write mechanism has the strong ability of expansion and the sharing mechanism of template image, the virtual machine does not send template image during migration. There is no need to transfer GB number of mirrored files. All the contents of Qcow files are sent to the file system corresponding to the destination node before the memory iteration begins. During the memory iteration process, real-time monitoring virtual machine writes to Qcow files and records dirty blocks. After each iteration, the dirty pages and dirty block records are sent to the destination node. After the destination node receives the data, the memory map and disk driver are called to map the data to the corresponding location, and the memory iteration process is optimized. It reduces the dirty pages generated by the virtual machine iterating over the heavy load, calculates the Hash value of the file contents in each monitoring record, and saves it in the cache. The files with the same Hash value are sent only once, thus reducing the amount of data transferred. The virtual machine online migration mechanism across the data center is implemented in this paper, which can realize the virtual machine online migration between the data centers under the premise of ensuring the normal operation of the business. Provides a basic approach to resource management between data centers. At best, the total migration time is within 120 s, and the downtime is less than 5 Ms. But the key factor to determine the total migration time is the size of the Qcow mirror file, The file increases proportionally with the increase of the file.
【学位授予单位】：西北师范大学
【学位级别】：硕士
【学位授予年份】：2013
【分类号】：TP302

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