vSphere DRS Automation Level Transition: Unresolved Impact of Switching from Partial to Fully Automated on Concurrent VM Migration Latency

Goal

To determine whether enabling Fully Automated DRS increases latency for concurrent vMotion requests compared to Partial Automation, and to identify the contributing factors.

Constraints & Uncertainty

• Latency is only measurable under high concurrent migration loads.
• Network bandwidth and host CPU contention may vary across clusters.
• DRS imbalance thresholds influence when migrations are triggered.

Open Questions

1. Does switching from Partial to Fully Automated DRS consistently increase perceived latency during simultaneous vMotion operations?
2. How do cluster imbalance thresholds modulate the latency spike observed in Fully Automated mode?
3. Are there documented mitigation strategies to reduce latency without lowering automation levels?