A: VMM 2012 comes with new features that greatly improve the clustering experience for Hyper-V hosts. One of those features, dynamic optimization, uses cluster-wide monitors and calculations to load balance virtual machines (VMs) across available Hyper-V hosts.
Another new feature, power optimization, provides a function for clusters that's similar in some ways, but very different in others. Dynamic optimization's job is to create the best balance of VMs across hosts, and power optimization is aimed at doing the same, while also consolidating VMs where possible. By consolidating VMs onto fewer hosts but still maintaining a balance of resources, Hyper-V servers that find themselves no longer hosting VMs can be safely powered down. Those same hosts can be powered on when balancing calculations require VMs to be migrated.Power optimization works together with dynamic optimization and any configured resource thresholds, and can be enabled or disabled separately from dynamic optimization. Because VMM 2012 was only recently released as a beta, additional details are still to come. Microsoft discusses more about power optimization on TechNet.