What setting in vSphere DRS affects how aggressively it recommends migrations for VM happiness?

The Migration Threshold setting in vSphere DRS is key in determining how aggressively DRS recommends migrations to optimize virtual machine performance and resource allocation. This setting allows an administrator to control the level of aggressiveness in migration recommendations based on resource usage.

When set to a higher threshold, DRS will recommend more frequent migrations to maintain optimal performance, prioritizing virtual machine happiness by balancing workloads effectively across hosts. Conversely, a lower threshold results in fewer migration recommendations, leading to a more conservative approach where DRS will only suggest moves when resource utilization is significantly imbalanced.

This flexibility in managing the migration strategy is vital for ensuring that virtual machines run optimally, helping to avoid performance bottlenecks while also considering the overall resource availability in the cluster.