Required permission to query orphaned VMDK files

Hi,

What is the specific required permission to query vSphere for orphaned vmdk files? Right now I have a ReadOnly permission and when I run my script, I'm getting an error complaining about the permission.

I know it's included in the Administrator role in vCenter, but I was wondering if that specific permission can be added to a custom role, without having to be given Administrator role?

Thanks in advance,

Alex