HA and DRS can be used together for load balancing along with failover. Together, HA and DRS bring out a more effective and balanced cluster, specially when HA initiates migrating its virtual machines to different hosts.
In case of a failover, HA takes control of the situation and restarts all the affected virtual machines on the other hosts. It also makes sure that the critical machines are made available with minimal downtime. Whenever such a situation arises, the hosts get over loaded with extra machines, while some are still functioning with abundant resources available at hand. If DRS is also enabled along with HA, then DRS ensures that it understands, and restarts or moves machines accordingly on different servers, in such a way which ensures smooth operations for all machines.
Storage DRS enables the administrator to manage the resources of a datastore cluster in the same way the DRS does for a host. Once Storage DRS is enabled, it recommends virtual machine disk placement and migration options to balance space and I/O resources across the datastores in the cluster.
To enable or disable Storage DRS, you can select or deselect the Enables Storage DRS option from the Datastore Cluster Settings dialog. You can follow the next steps to configure Storage DRS:
- Login into vCenter using vSphere Web Client.
- Select the desired datastore cluster.
- Go to the Manage tab and click Settings.
- Under Services, click Storage DRS and then click Edit.
- Select Turn On vSphere DRS.