WordPress MU

I have WPMU running several different sites on subdomains and the domain mapping plugin mapping them to their own domain names. My question is how do I use the robots.txt file and have sitemaps for each. I looked in Google Webmaster tools and they each appear to have their own independent robots.txt files but I can't seem to find them. According to google it is in the mapped domains root, but that doesn't acctually exist because those domains aren't hosted they are just parked. Any help would be appreciated.

Anyone?

Domain mapping basically takes everything in the MU site and makes it appear as if it's from a different domain. So the one robots.txt file works for all of them.

If they need to be different for each subdomain, quite normal for sitemaps, you may want to look for a plugin to generate them dynamically rather than using a static xml file.

Thanks for the clarification!