Running ESXi 6.5.0 with a NetApp C190 SAN that we just expanded with more drives. Prior to adding the new drives, we had two datastores: DS1 (8.7TB total / 1.5TB free) & DS2 (8.3TB total / 3.5TB free). Due to our threshold settings, DS1 would constantly show a low space warning. After configuring new drives on the NetApp, and using vSphere to assign the new space to the existing datastores, we have the following: DS1 (11.8TB total space), DS2 (11.3TB total space). Everything looked good for a day and a half and then suddenly I get vSphere alert that DS1 has low space again. I look at the storage and datastores through vSphere, and DS1 is now showing the original 8.7TB w/ 1.5TB free. I look at the NetApp, and there are no errors and it still shows the correct available volume and LUN space. In vSphere I click on DS1 and tell it to refresh/recalculate, and after a few seconds it now shows as 11.8TB total. Thought this was a one time glitch, but a few hours later it did the same thing and DS2 also reverted back to showing the old total space. What in the world is going on? I restarted the vCenter virtual appliance thinking maybe it needed it after adding the new storage but that didn't do anything positive. I don't see any other alerts or errors on either the ESX environment or the NetApp. Not sure what is going on.....
