Improving Virtual Machine Migration in Federated Cloud Environments

Cloud federation is the future of the cloud computing. In such new emerging scenarios, the "hot" and "cold" migration imply the movement of a virtual machine disk-image from a server placed in a cloud provider to a server placed in another one, with a consequent consumption of bandwidth and cloud resources. This paper aims to reduce such costs proposing a Composed Image Cloning (CIC) methodology. Our approach does not consider the disk-image of a VM as a single monolithic block, but as a combination between "composable" and "user data" blocks. Since the former may be cloned locally in the destination clouds, the amount of data which have to be transferred may be reduced. In order to test our strategy we implemented a real test bed extending the OpenQRM platform. Experiments show the validity of the proposed approach in large-scale federated cloud environments, where the amount of data transferred significantly reduces when the number of live migrations increases.