Cluster Overview

vSphere supports grouping ESXi hosts that are managed by the same vCenter Server system into clusters. Clusters take advantage of features such as VMware DRS and VMware HA.

• VMware HA (VMware High Availability) fails over virtual machines from one host in a cluster to another host, in the event of host failure.
• VMware DRS (VMware Distributed Resource Scheduler) provides dynamic redistribution of resources. DRS also includes support for Distributed Power Management (DPM), which makes recommendations or decisions to power off hosts and power them on again as needed, to save energy.

  You can set up VMware DRS to automatically migrate virtual machines, or to display recommendations if resources are not used efficiently across the cluster.

See Creating and Configuring Clusters and Managing DRS Clusters.