Dynamic consolidation of virtual machines （VMs） in a data center is an effective way to reduce the en- ergy consumption and improve physical resource utilization. Determining which VMs should be migrated from an over- loaded host directly influences the VM migration time and increases energy consumption for the whole data center, and can cause the service level of agreement （SLA）, delivered by providers and users, to be violated. So when designing a VM selection policy, we not only consider CPU utilization, but also define a variable that represents the degree of resource satisfaction to select the VMs. In addition, we propose a novel VM placement policy that prefers placing a migratable VM on a host that has the minimum correlation coefficient. The bigger correlation coefficient a host has, the greater the in- fluence will be on VMs located on that host after the migra- tion. Using CloudSim, we run simulations whose results let draw us to conclude that the policies we propose in this pa- per perform better than existing policies in terms of energy consumption, VM migration time, and SLA violation per- centage.
