vCenter Server storage status displays as unknown
All Element OS versions
Q: Why does vCenter Server Storage Status display as Unknown?
A: The Storage Status is reported by the Datastore usage on disk alarm, which monitors datastore disk usage. This is a pre-configured alarm and it triggers automatically when problems are detected. This issue may occur if you have disabled the action for this alarm.
Enable the alarm so the proper alert status is visible.
To enable the alarm please reference the following VMware KB.