Towards synchronization of live virtual machines among mobile devices

The mobile computing experience would improve if users could switch seamlessly from one device to another, with both data and computation state preserved across the switch without apparent delay. This paper proposes VMsync, a system for synchronizing the state of live virtual machines (VMs) among mobile devices. VMsync seeks to incrementally transfer changes in an active VM on one device to standby VMs in other devices, so as to maintain a consistent VM image and minimize switching latency. However, constraints of the mobile environment make these goals difficult to achieve and raise many research questions. We present our preliminary design for VMsync and a feasibility study aimed at determining how much data would need to be transferred under different mobile workloads and synchronization policies. For example, through experiments with a Xen VM running Android and playing a YouTube video, we show that sending dirty memory pages transfers 3 times more data than sending only the bytes that actually changed in those pages. Overall, we conclude that VMsync is a feasible approach deserving of further research.