Vshadow: Promoting Physical Servers into Virtualization World

Abstract

Though virtualization technology has been widely adopted these years due to its advantages on improving server utilization, reducing management costs and energy consumption, there are still lots of legacy applications deployed in traditional physical machines. How to efficiently promote these physical servers into virtual machines (VMs) if necessary has become an interesting and challenging problem. Existing Physical-to-Virtual (P2V) conversion methods suffer from long server downtime during the converting process, which makes them impractical and inefficient in real world. In this paper, we analyze the reason why the previous approaches result in intolerable server downtime, and propose a new P2V conversion system called Vshadow. It enables a native P2V conversion which can quickly switch physical machine to a local VM, and combines implicit disk replication method and live migration process to promote physical machine into remote virtualization platform. Our experimental results show that Vshadow can reduce the server downtime by more than 90 % compared with existing P2V conversion methods. Besides proving the effectiveness and efficiency of Vshadow, we also illustrate the possible ways to apply Vshadow in server consolidation of cloud data centers and to use Vshadow to build a cost-effective failover system.