基于KVM的虚拟锁步技术

Virtual lockstep technology based on KVM

依托基于内核的虚拟机(kernel-based virtual machine,KVM)的平台,针对虚拟机容错系统中的关键技术——虚拟锁步技术展开研究,主要研究虚拟锁步技术所采用的虚拟机同步机制(VM synchronization mechanism)。对开源虚拟机容错软件Kemari进行架构剖析与代码分析,指出其所使用的基于数据拷贝的虚拟机同步机制在不使用共享存储进行锁步运行时,具有一定性能缺陷;以此为基础,提出相应的改进措施,设计并实现一种新的虚拟机同步机制。该机制采用事件重放的方式实现冗余虚拟机间块设备数据的同步,弥补了Kemari虚拟机同步机制的相关性能缺陷。

The virtual lockstep technologies ,especially the virtual machine synchronization mechanism were studied relying on the popular virtual machine platform KVM .First ,the fault-tolerant software architecture and project based on the KVM virtual machine platform Kemari was analyzed .Then ,the problem was pointed out that due to the use of virtual machines synchroniza-tion mechanism based on the data copy ,Kemari’s virtual lockstep technology had certain performance deficiencies when it ran without the use of the shared storage .And a new VM synchronization mechanism named Forever based on improvements of the Kemari VM synchronization mechanism was proposed .The new VM synchronization mechanism combined two kinds of data syn-chronization methods .When virtual machine fault-tolerant system runs without the shared storage ,Forever realizes redundant block device data synchronization in the way of event replaying .At last ,the implementation details of new VM synchronization mechanism were introduced .