Hello,
I will reply to you with English.
Based on my understanding, you just want to upgrade your 2012 DC to the 2019 DC, right?
If i misunderstand you, feel free to let us know.
The minimum requirement to add a Windows Server 2019 Domain Controller is a Windows Server 2008 functional level. The domain also must use DFS-R as the engine to replicate SYSVOL.
If you want to check if the DFSR is used for the Sysvol replication, the following command can be used:
Command:
dfsrmig.exe /getglobalstate
If the Result: 3 (ELIMINATED) the DFSR is used for the replication.
If not, FRS should be migrated to DFSR:
https://learn.microsoft.com/en-us/windows-server/storage/dfs-replication/migrate-sysvol-to-dfsr
Before Migrate the FRS TO DFSR, make sure the functional level is 2008 or higher.
To raise the forest functional level
Open Active Directory Domains and Trusts. To open Active Directory Domains and Trusts, click Start, click Administrative Tools, and then click Active Directory Domains and Trusts.
In the console tree, right-click Active Directory Domains and Trusts, and then click Raise Forest Functional Level.
In Select an available forest functional level, select the value and then click Raise.
Then before adding the new dc, we should also make sure everything is working well, following command for your reference:
Dcdiag /v >c:\dcdiag1.log
Repadmin /showrepl >C:\repl.txt
Repadmin /showreps *
Last, the new DC can be added, following for your reference:
https://www.petenetlive.com/KB/Article/0001262(third-party link)
Please note that:
It is suggested having at least 2 DCs in one single domain.
Before any critical changes for the DCs, remember to do a full backup of the DCs
This response contains a third-party link. We provide this link for easy reference. Microsoft cannot guarantee the validity of any information and content in this link.
Best Regards,