How to Scan Esxi 6.5 or vSphere 6.5

How to Scan Esxi 6.5 or vSphere 6.5

I really don't want to scan the vm's that are associated with vsphere I just want to get the physical hardware information.  I have tried this a few different ways and haven't had any luck. 

We have created a user in vSphere and gave it read-only permissions.  We than added this user as a Vmware-Credential in the credential store.  I have tried to use this user to scan the individual hosts as well as the vcenter server.  I always get a "credential not configured" error.  I really, really DO NOT want to use and administrative user to do this nor do I want to use a local user on the esxi host.  

Should I be doing this some other way (IPMI, SNMP)?  Has anyone else had success doing this?

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