I have 3 DCs (2x Win 2008 R2 DC and 1x Win 2003 Ent DC). I am going to demote Win 2003 DC from the environment. I have moved all master roles long time ago. To understand if everyting alright, I have shutdown Win 2003 DC this morning (did not demote yet, just to simulate
Exchange 2010 server's EMC start having difficulties to find DC. After a couple of try eventually EMC succesfully connected to one of Win 2008 R2 DCs.
Outlook 2010 conneting to server with delay.
OWA had given Server busy try later error for a while but now it is OK.
Beside of above issues I haven't noticed any other problem yet.
I will keep the Win 2003 DC off for a week. According to symptoms above what shoudl I do? Why Exchange Server acting like that and what should I do to repevent future problem while demoting the Win 2003 DC.