DRS automation levels can be configured when/after enabling DRS on a cluster.
DRS automation levels define how DRS reacts to compute resource imbalances in a cluster and whether it requires little or no manual intervention. DRS can choose to apply the generated migration and initial placement recommendations or present them on the vCenter GUI for the administrator to take action on them.
By default, DRS works in Fully Automated mode. You can, however, set it to Manual or Partially Automated mode:
Let's describe the use of these automation levels:
- Manual mode: This generates and presents the initial placement and migration recommendations. This requires the administrator to action them.
- Partially automated mode: This generates and executes the initial placement recommendations. The migration recommendations that are generated need to be actioned by the administrator.
- Fully automated mode: This automatically carries out both initial placements and migrations.
If there is more than one migration recommendation, then the administrator is given a prioritized list of recommendations to choose from.
Initial placement refers to the process of choosing an ESXi host from a DRS cluster to power on or resume a VM. DRS generates these recommendations by choosing an ESXi host that has enough resources to run the VM that is being powered on or resumed.
Initial placement refers to the process of choosing an ESXi host from a DRS cluster to power on or resume a VM. DRS generates these recommendations by choosing an ESXi host that has enough resources to run the VM that is being powered on or resumed.
The following table compares how migration recommendations and initial placements are dealt with, based on the DRS automation level that's been configured on the cluster:
| DRS automation level | VM migrations (vMotion) | VM initial placements |
| Fully automated | VMs are automatically migrated. | VMs are automatically powered on or resumed on a suitable ESXi host. |
| Partially automated | Migration recommendations are presented. The administrator has to manually apply one of the migration recommendations. | VMs are automatically powered-on or resumed on a suitable ESXi host. |
| Manual | Migration recommendations are presented. The administrator has to manually apply one of the migration recommendations. | Placement recommendations are presented. The administrator has to manually apply one of the recommendations. |