From what I can see from the oms status the following will need to be modified with the new domain name:
Console Server Host
Admin Server Host
Managed Server Instance Host
The question remains as to the best approach/method to accomplish this.
Wow, Oracle's response was not what I had hoped for:
I am Arun from Oracle Support.I will be assisting you further on this SR.
I am sorry to say but you would have re-install the complete Cloud control, including all the agents. As the hostname will be deply embeded in numerous files and it will be impossible to change each and every file.
So I would suggest a re-install if you want to change the domain name
Let me know if you need more information
You can do this, but you'll need to treat it as a restore/recovery scenario. Backing Up and Recovering Enterprise Manager --- follow OMS restored on different host procedures.
There's a slight chance that you might be able to "fake it" with the hosts files to get the system started again, but not sure about Windows....
Worked with Oracle support for a while on this one but it got way out of hand on time required to accomplish this all. I gave up and will probably forgo using EM12c for a while. I guess I can start over from scratch when I have time, as Oracle suggest.