After migrating datastores to datastore clusters and adding permissons at datastore cluster level I run into incomprehensible issues where users suddenly failed to create VMs. Users getting an error messege while selecting the Cluster:
You do not have the privilege 'Datastore > Allocate space' on the datastore connected to the selected Cluster
I checked the vCenter permissons and noticed that the datastore permission is missing. I remembered that there was this bug that causes all vCenter permissons to disappear after renaming Windows users or groups, so i just reassigned the permisson. Shortly later the problem recurred, so I searched the VMware KB and noticed that this is a known issue: KB: 2008326
VMwares resolution is to place the datastore cluster inside a folder, set the permissons to that folder and propagate them. Unfortunately you can't simply move the cluster:
Move entities - The specified folder does not support this operation.
The solution is to create a new storage cluster, recreate all settings and move the VMFS-Datastores into the new cluster. This task is doable withou any interruption to the running virtual machines.