Xen虚拟化环境中镜像文件的访问直接映射研究

摘要

In consideration of the problem that in current virtualization environment, image files suffer from severe performance degration for their manifold access mapping proceedings, a direct access mapping mechanism for image files in the Xen virtualization environment was put forward, and based on the mechanism, a direct access mapping algorithm for access of virtual devices to physical devices was designed and implemented. This mechanism can remove the extra processing in the traditional access mapping proceedings of image files and improve their I/O performance. The experimental results show that this optimization can achieve up to 28% of performance improvement compared with the traditional image files.%针对虚拟化环境中镜像文件模式虚拟块设备因繁琐的访问映射过程而造成的性能低下问题,提出了一种Xen虚拟化环境中镜像文件的访问直接映射机制,而且提出了在此机制下面向镜像文件模式的虚拟块设备到物理块设备的访问直接映射算法.根据此算法,实现了虚拟块设备和物理块设备之间的访问直接映射,该机制简化了镜像文件模式虚拟块设备I/O访问过程中繁琐的访问映射过程,有效地提高了镜像文件的I/O性能.试验表明,相对于传统的镜像文件,这样的访问直接映射可使镜像文件的I/O性能提高28％.