There is an expansion in research on energy efficiency in a large-scale data center or server clusters in the past few years. In this section, we only review the work related to VM management and cloud computing since they are more closely related to this work.
One most important technology that makes cloud computing possible is the use of virtualization (He et al., 2016; Clark et al., 2005; Wan et al., 2016, Wood et al., 2007). Virtualization allows consolidation of a number of smaller workloads into partitions of a larger physical server, while the user achieves the same level of performance and security at a lower management cost and possibly lower hardware cost (Verma et al., 2008, Deshpande et al., 2016).