Dynamic Optimization (DO) is a new VMM feature that initiates live migration of VMs that are on a cluster, to improve load balancing among cluster nodes and to correct any placement constraint violations.
It can be configured with a specific frequency and aggressiveness on a host group, which determines the amount of load discrepancy required to trigger a live migration through Dynamic Optimization (DO).
Dynamic Optimization settings can be configured for the CPU, memory, disk I/O, and network I/O.
By default, VMs are migrated every 10 minutes with medium aggressiveness. You must take into consideration the resource cost (for example, the network) of extra migrations against the advantages of load balancing among cluster nodes, when setting the frequency and aggressiveness for Dynamic Optimization.
Power Optimization , a Dynamic Optimization optional feature...