Hierarchical Copy Algorithm for Xen Live Migration

With the increasing number of technology areas using Virtual Machine (VM) platforms, challenges exist in Virtual Machine migrating from one physical host to another. This paper presents the design and implementation of a novel Hierarchical Copy Algorithm (HCA) for Xen live VM migration. Based on the memory characteristics which will be transferred, the measuring time of working sets is shifted to the earlier migration stage. Furthermore, dirty page is recorded from “0/1” token to precise modification times. Experimental results illustrate that our HCA approach can shorten both the total migration time and downtime obviously under high dirty page rate environment.