Optimized live migration using NRU and modified clock policy

Live Virtual Machine Migration is the key feature of virtualization to support business activities especially in data centers and provides load balancing, power management, fault tolerance and online maintenance. Though pre-copy is a principal approach for live VM migration, heavy workloads would decrease the quality of services; consequently, using an effective method is necessary. This paper will elaborate on pre - copy method and improved it on Xen 4.1.2 with taking advantages of clock policy for tracking updated memory pages. By using Clock technique and innovative one, it can examine all running pages rotationally and prevent to transmit those frequently updated pages repeated. This can ensure those updated pages which are in working set, are transmitted just once in the iteration process. Experiment demonstrates that compared with pre-copy, the proposed technique can reduce 34% of number of sent pages and total migration time on average without increasing down time specially.