DRS creates resource pools spanning all hosts in the cluster and applies cluster-level resource allocation policies. In addition to resource pools and resource allocation policies, DRS offers the following resource management capabilities:
When a virtual machine in a cluster is powered on, DRS places it on an appropriate host or generates a recommendation depending on the automation level you have chosen.
DRS distributes virtual machine workloads across the vSphere hosts inside the cluster. DRS continuously monitors the active workload and the available resources and performs or recommends VM migrations to maximize workload performance.
When enabled, Distributed Power Management (DPM) compares cluster-level and host-level capacity to the demand of the VMs, including recent historical demand, and can then place vSphere hosts in standby mode or power them back on as capacity needs change. DPM can also be set to simply issue recommendations for power on/power off operations.
Cluster Maintenance Mode
DRS speeds up the VMware Update Manager remediation process by determining the optimum number of hosts that can enter maintenance mode simultaneously, based on current cluster conditions.
DRS redistributes VMs across vSphere hosts as needed to adhere to user-defined affinity and anti-affinity rules following host failures or hosts being placed in maintenance or standby mode.