Drobo and S3 sync or write-through

Hi all,

we want to use a DroboPro as both back-up and 3rd storage from an Apple Xserve file-server. However, we’d also like to use Amazon S3 as a 2nd back-up and customer interface. We want every save to our Drobo to instantly reflect in S3, a sort of ‘write-through’ solution from Drobo to S3. Or instant sync between Drobo and S3.

The application is images libraries for print-shop customers.

In your opinion, what is the best way to do this?