How do I add mirrors? How does Smart choose which mirror to use?
In the GUI, go to Edit->Mirrors, click “New” and set your Origin URL and Mirror URL. Most likely you will be using whatever it is that you used as Base URLs for your repositories as Origin URLs. You may add as many Mirror URLs to an Origin URL as you wish, and you shouldn’t worry too much about slow mirrors and mirrors going out of date. Smart automatically handles bad/inefficient mirrors and avoids them in the future.