vCloud Usage Meter
The installation of vCloud Usage Meter OVF Appliance is very easy, just remember to assign its network NIC to your vCenter subnet and then browse to http://vCloudUsageMeter:8080/serviceprovider, add vCenter and configure all the email settings.
I found vCloud Usage Meter is very useful even you are not using vCloud Director, it serves as a good measurement of your virtual infrastructure and you can generate reports to have a better understanding of your VM usage, best of all, it’s a free!