Improving the efficiency of deploying virtual machines in a cloud environment

Flexible allocation of resources is one of the main benefits of cloud computing. Virtualization is used to achieve this flexibility: one or more virtual machines run on a single physical machine. These virtual machines can be deployed and destroyed as needed. One obstacle to flexibility in current cloud systems is that deploying multiple virtual machines simultaneously on multiple physical machines is slow due to the inefficient usage of available resources. We implemented and evaluated three methods of transferring virtual machine images for the Open Nebula cloud middleware. One of the implementations was based on BitTorrent and the other two were based on multicast. Our evaluation results showed that the implemented methods were significantly more scalable than the default methods available in Open Nebula when tens of virtual machines were deployed simultaneously. However, the implemented methods were slower than the default unicast methods for deploying only one or a few virtual machines at a time due to overhead related to managing the transfer process. If the usage pattern of the cloud is such that deploying large batches of virtual machines at once is common, using the new transfer methods will significantly speed up the deployment process and reduce its resource usage.