Here is a video on YouTube detailing NetApp support for vCloud Director:

http://www.youtube.com/watch?v=QzaDP3pKB4s

It is important to note that for a backup solution to support vCloud Director, vCLoud Director API’s need to be supported so that the vApp Metadata can be backed up along with the vApp vmdk files.

In addition to this video here is a PDF from NetApp, detailing storage design best practice:

http://media.netapp.com/documents/tr-3866.pdf

Worth investigating if you are a NetApp customer.