"Unable to put the host in maintenance mode" during cluster remediation

Products

• VMware vSphere ESXi

Issue/Introduction

• Cluster remediation task fails with error, 'Unable to put the host in maintenance mode'.
  
  
• Verifying /var/log/vmware/vmware-updatemgr/vum-server/vmware-vum-server.log on the vCenter Server: 
  Host host-<id> could not go into maintenance mode for following reason : Virtual machine 'Z-VRA-<machine-name> on host '<host-name>' would violate a virtual machine - host affinity rule
  
  
• Affinity Rule are set on every ESXi host and Zerto VMs are pinned to the ESXi hosts in the cluster. 

Environment

vSphere ESXi

Cause

The issue occurs because Zerto VMs are configured with "must run" affinity rules. Note that manually placing a host in maintenance mode automatically shuts down the Zerto VMs, but cluster-level vLCM remediation fails as it cannot migrate or automatically power off the VM.

Resolution

1. Manually power off the Zerto VM's on every ESXi host.
2. Manually power off the Zerto Site  (Validate with Zerto support before executing the steps in the below article)
3. Change the option under Remediation Setting and choose : "Power Off Virtual Machine"
   [The remediation setting is located here: Menu > Lifecycle Manager > Settings > Host Remediation > Baselines > Edit]