Unmounting the datastore failed to remove from vCenter 'Not connected and accessible host is attached to this'

Products

• VMware vCenter Server

Issue/Introduction

While unmounting the datastore from the vCenter which is already been deleted from backend, fails with error: "Not connected and accessible host is attached to this datastore"

Environment

VMware vSphere 6.x

VMware vSphere 7.x

VMware vSphere 8.x

 

Cause

vCLS VMs residing in the datastore cause the removal process to fail.

Resolution

Enable Retreat mode on cluster to remove vCLS VMs from datastore.

1. Navigate to Cluster > Configure > vSphere Cluster Services > General.
2. Click Edit vCLS Mode, then change it to Retreat Mode.
3. Wait for vCLS process to disable completely.
4. Remove/unmount datastore.
5. Remove Retreat mode on cluster once datastore is removed.