VMware DRS helps improve resource allocation across all hosts and resource pools.

DRS collects resource usage information for all hosts and virtual machines in a VMware cluster and gives recommendations or automatically migrates virtual machines in one of two situations:

Initial placement

When you first power on a virtual machine in the cluster, DRS either places the virtual machine or makes a recommendation.

Load balancing

DRS tries to improve CPU and memory resource use across the cluster by performing automatic migrations of virtual machines using vMotion, or by providing recommendations for virtual machine migrations.