Two separate businesses using the same domain name have now merged into one.
This is the first time I've ran into this and hope someone could shed some light. We've recently acquired a new client who at one point had two domain controllers. Server 2008 and Server 2012. They moved Server 2012 over to a new location as part of a different business, but kept the same domain name. Server 2008 AD sees the 2012 as a DC, However 2012 doesn't see 2008 as a DC. They are now on different networks, but recently was configured to tunnel back to corporate to share resources.
What I'm trying to accomplish: Join a 2016 DC to their corporate to decommission 2008.
Error I'm getting when promoting 2016 to a DC: "Active Directory preparation failed. The schema master did not complete a replication cycle after the last reboot."
What I've gathered so far.
Server 2008 - DC - samedomain.local - Corporate Office
At one point was replicating to 2012.
Server 2012 - DC - samedomain.local - Remote Office
No longer replicating from 2008.
Recently a WatchGuard VPN was put in so the two locations could talk and share resources. Different IP schemes, and they don't know about each other.
My Question: Can I safely remove 2012 DC from 2008 to stop attemping replication and at the same time continue to operate both under the same domain names, but seperate?
Remote Office will still use 2012 to authenticate locally until we can sit down and plan out a migration plan several months from now.
Corporate will still use 2008 to authenticate locally.