I created a 15TB vol and I have 2 NFS shares which I set a 3TB hard limit.  Security style is mixed, Permissions are set to everyone and BuiltIn\Users to full control.  When I mount the volume in either Windows or Unix the volume shows the full capcity and not the 3TB  hard limit.
 
I ran the following commands:
quota status - quotas are on for the volume
quota report - which didn't report anything for the volume that I applied the quota
quota report <path> - which returned (no quota for the file <path>)
 
I haven't tried turning the quota off and back on.  I'm not sure if that will fix the problem but I wanted to see if anyone had suggestions.
 
Thanks