  Datacenters (DCs) are deployed in a large scale to support the ever
increasing demand for data processing to support various applications. The
energy consumption of DCs becomes a critical issue. Powering DCs with renewable
energy can effectively reduce the brown energy consumption and thus alleviates
the energy consumption problem. Owing to geographical deployments of DCs, the
renewable energy generation and the data processing demands usually vary in
different DCs. Migrating virtual machines (VMs) among DCs according to the
availability of renewable energy helps match the energy demands and the
renewable energy generation in DCs, and thus maximizes the utilization of
renewable energy. Since migrating VMs incurs additional traffic in the network,
the VM migration is constrained by the network capacity. The inter-datacenter
(inter-DC) VM migration with network capacity constraints is an NP-hard
problem. In this paper, we propose two heuristic algorithms that approximate
the optimal VM migration solution. Through extensive simulations, we show that
the proposed algorithms, by migrating VM among DCs, can reduce up to 31% of
brown energy consumption.
