Missing vCLS VMs in cluster

Products

• VMware vCenter Server 7.0
• VMware vCenter Server 8.0

Issue/Introduction

• Cluster has a warning "vSphere DRS functionality impacted by unhealthy state of the vSphere Cluster Services" 
• There are no vCLS VMs in the Cluster. 
• Enabling and disabling Retreat mode does not help to recreate the vCLS VMs.

Environment

VMware vCenter 7.x
VMware vCenter 8.x

Cause

• This issue can occur when there are no datastores available for the vCLS VMs to get created and all the datastores in the cluster are Solution blocked. 
• It can be verified by navigating to Cluster --> Configure --> vSphere cluster services --> Datastore 
  

Resolution

• It is necessary to investigate why all the datastores are blocked by the Solution (vSAN / SRM etc., )
• As a workaround, add a new datastore to the cluster and the vCLS VMs can get created on that datastore.