You must be having Luns presented to your ESX hosts using FCP. This is is known issue in WFA for VC Datasource. This bug has already been identified and its fix should be available in the next WFA release which is expected very soon.
Till then we regret your inconvenience.
If this post resolved your issue, help others by selecting ACCEPT AS SOLUTION or adding a KUDO.
Yeah, most of our environment is running on Fibre Channel; we just recently started to explore NFS for vmware which ironically is the reason I'm excited about WFA. I was hoping to use WFA to deploy 88 NFS datastores without using the extremely slow, tedious, and crash happy VSC plugin. The bugs in the current release keep getting in my way though, really sad news that a stable version wont be available soon enough to help me out this time.
Re: vc datasource: Duplicate entry '-1499422296' for key 'PRIMARY'