When you attempt to put a datastore into maintenance mode, the same affinity or anti-affinity rule violation fault might appear to be listed more than once in the Faults dialog box.
The Faults dialog box appears to display multiple instances of identical faults, but in fact, each fault refers to a different datastore. The Faults dialog box does not list the names of the datastores, which causes the faults to appear to be redundant.
The Faults dialog box always displays a separate rule violation fault for each datastore that is considered for placement. If you want the datastore to enter maintenance mode, remove the rule that prevents the virtual machine from being migrated.