All, I have submitted the initial revision of a patch to support S3 backing NFS secondary storage (https://reviews.apache.org/r/8123/). I have opened ticket CLOUDSTACK-509 to track the testing and delivery of the enhancement. I have also created a design document in the wiki roughly following design document template. Since I am not a committer, it did not seem appropriate for me to add a reference from the roadmap to the ticket.
In its current state, I have tested the single zone template and ISO functionality on devcloud. I am working to configure a multi-zone integration testing environment to complete all test scenarios outlined in the design document. My plan is to refine the arch per community patch concurrently with the completion of integration testing and bug squashing. I look forward to your feedback, -John
