I have been looking around for a good answer to this question for a while now but not found anything definitive. I would like to host all uploads across my multisite on a CDN, preferably Amazon S3.
My set up is a subdomain install with most blogs having mapped domains, I also want to avoid a scenario where I have to configure options for each blog individually (as we're getting about 40 new blogs per month). My question is, is this possible?
My guess would be that I need to move the blogs.dir to Amazon s3 and then create a mu-plugin, or make a settings alteration in my db to tell wordpress to create new blog.dir directories on amazon s3 and upload all files to their. However, I'm wondering if you have any wisdom you could offer on the matter?