Just as an example app. Basically, use S3 the same way you use an in house SAN. Also, if I remember correctly, S3 integration is per account, and only if you

Just as an example app. Basically, use S3 the same way you use an in house SAN. Also, if I remember correctly, S3 integration is per account, and only if you enable the external file storage app. It wouldn't let you store all data on S3. So, mounting a bucket as the OwnCloud data folder would be the way I'd get that.