The limitation of Proactive HA in 2-node vSphere HA cluster

Products

• VMware vSphere ESXi
• VMware vCenter Server

Issue/Introduction

Symptoms:

• VM with soft affinity rule (VM should be present on ESXi) cannot execute vMotion to another ESXi and then the ESXi can't be put into maintenance mode automatically by Proactive HA.

Environment

VMware vSphere ESXi 7.x
VMware vSphere ESXi 8.x

Cause

VM with soft affinity rule cannot be migrated to another ESXi because resource check for evacuating VM failed due to 2-node vSphere HA cluster. By doing this the ESXi can't be put into maintenance mode automatically by Proactive HA.
This behavior is per design, because if one host is placed into maintenance mode there would only be one host left and therefore HA wouldn't be able to perform a failover for VMs.

Resolution

Currently, there is no resolution.

Workaround:
Add one extra host into the cluster(Must be 3 or more nodes).