What determines if vSphere DRS makes migration recommendations or automatically places VMs on hosts?

The automation level is critical in determining how vSphere DRS (Distributed Resource Scheduler) interacts with virtual machines (VMs) and hosts within a cluster. This automation level can be set to different levels, which dictate the behavior of DRS regarding VM placement and migration recommendations.

When the automation level is set to "fully automated," DRS takes control and automatically places VMs on hosts based on resource utilization, ensuring optimal distribution of workload. Conversely, when the automation level is set to "manual" or "partially automated," DRS can still provide migration recommendations, but it will not execute them autonomously. Instead, it requires an administrator's intervention to manually migrate VMs.

Different automation levels allow administrators to fine-tune DRS behavior based on specific organizational needs and workloads, balancing between automation and manual control. Thus, it is the automation level specifically that governs whether DRS makes migration recommendations or takes automatic actions on VM placements.