Provisioned Space and Used Space show 0KB

Ran into this issue earlier today when I was trying to get sizes of VMs in vCenter. A half of my machines were showing 0.00 B for their Provisioned and Used Space.

The solution was simple enough after scratching my head for a little bit. Select the server in vCenter and go to Configuration Tab. Select the Storage Adapters under Hardware. In the top right hand corner you will see Rescan All... click that and click OK at the next screen. vCenter will now fires off a rescan of your HBAs and your VMFS volumes and does a "Recompute Datastores Groups". Once that is done it should now show your Provisioned and Used Space without issue.

Sometimes it is the simple things that drive you crazy!!