Error unmounting VMFS : The vSphere HA agent on host ‘‘ failed to quiesce file activity on datastore

Scenario:  When unmounting a datastore I got the following error on an ESXi 5.1 hosts:  The vSphere HA agent on host ‘<host>’ failed to quiesce file activity on datastore ‘/vmfs/volumes/xxxxxxx-xxxxxxxxx-xxxxxxxxx-xxxxx’. To proceed with the operation to unmount or remove a datastore, ensure that the datastore is accessible, the host is reachable and its vSphere HA Read More…