Hello, can I add a Windows 2012 R2 server to UCS and give it an AD role as a backup server? The idea here is to use UCS, but keep my exchange server until we are comfortable with another mail server solution.
I may be wrong and/or have not enough experience but for me there are different strategies to - run UCS in an Active Directory Enverinment, see 9.3. Active Directory Connection- Migrate from AD to UCS, see 9.5. Migrating an Active Directory domain to UCS using Univention AD Takeover
You can sure add UCS to your AD and use some features but it doesnt look like this machine can be easily promoted.