I recently set up a multisite installation using subdomains, and then installed the WordPress MU Domain Mapping plugin. I am running Nginx on an Amazon EC2 Ubuntu instance.
What I am trying to accomplish is to host two different WordPress sites, mydomain1.com and mydomain2.com. Consequently, I have created a site called subdomain.mydomain1.com and set it up to map to mydomain2.com. So far, I can access the WordPress admin panel through mydomain2.com/wp-admin (but not subdomain.mydomain1.com/wp-admin). This is fine, but when I upload files through the media uploader, it creates a permalink such as subdomain.mydomain1.com/.../file.png. Instead, what I want it to do so to create a permalink to mydomain2.com/.../file.png, which works perfectly.
After doing some research, I am guessing this has something to do with my Nginx configuration file and that I am probably missing something. Does anyone have any suggestions on how I can get media uploads to permalink to the mydomain2.com domain?