I recently set up two wireless controllers (2000 series) with a total of 7 access points. The first controller was already running with a total of 5 ap's. I fired up the second controller, and got everything configured and added one access point to it. Everything was running fine yesterday, I had a few clients on the new controller and the rest on the old one. When I got in this morning and checked out the new controller, I saw that all of the access points had moved over to the new controller, and by extension all of the clients. The old controller now has nothing on it as far as ap's or clients. Is this supposed to happen? I didn't know mobility groups shifted over ap's as well? My only concern is that I have one more ap to set up which will make seven and the 2000 only supports 6 ap's. When I fire it up, will one of the ap's move back to it's original controller? Any input is appreciated. Thank you.
Have a look at this info which may help;
AP Fail-over Between Different Mobility Groups
From this good Troubleshooting doc;
Hope this helps!