An ESXi host has been placed into Quarantine Mode by Proactive HA. What will happen?

When Proactive HA places a host in Quarantine Mode due to a partial hardware failure signal, vSphere DRS attempts to evacuate VMs from the degraded host via vMotion. However, migrations are conditional - if relocating a VM would violate a DRS affinity or anti-affinity rule, or if no suitable destination host exists, the VM remains on the quarantined host. This selective, rules-aware evacuation is the key behavioral difference between Quarantine Mode and full Maintenance Mode.

Quarantine Mode prevents new or newly powered-on VMs from being placed on the degraded host when alternatives are available; the host is not used for workload balancing.

Quarantine Mode does not trigger unconditional full evacuation - DRS migrations are subject to cluster rules and capacity constraints, making complete removal of all VMs from the host not guaranteed.

vSphere HA failover is triggered by complete host or VM failure events; Quarantine Mode is a Proactive HA response to partial hardware degradation and does not initiate HA-driven failover actions.