VMFlow: Leveraging VM Mobility to Reduce Network Power Costs in Data Centers

Networking costs play an important role in the overall costs of a modern data center. Network power, for example, has been estimated at 10-20% of the overall data center power consumption. Techniques to save power in data centers have traditionally focussed on server power reduction through Virtual Machine (VM) migration and server consolidation. Most VM placement and migration techniques do not taken into account network topology and current network traffic. On the other hand, recent techniques to save network power have not yet utilized the various degrees of freedom that current and future data center will soon provide. These include VM migration capabilities across the entire data center network, on demand routing through programmable control planes, and high bisection bandwidth network architectures such as VL2, Portland and BCube.

This paper presents VMFlow: a framework for placement and migration of VMs that takes into account both the network topology as well as network traffic demands, to meet the objective of network power reduction while satisfying as many network demands as possible. We present network power aware VM placement and demand routing as an optimization problem. We show that the problem is NP-complete, and present a fast heuristic for the same. Next, we present the design of a simulator that implements this heuristic and simulates its runs over a data center network with a CLOS topology. Our simulation results using real data center traces demonstrate that, by applying an intelligent VM placement heuristic, VMFlow can achieve 15-20% additional savings in network power while satisfying 50-60% more network demands as compared to recently proposed techniques for saving network power