Hello Puneet Chauhan,
Thank you for posting in our Q&A forum.
Based on the description, you installed DC DNS, DHCP, FS, PS and IIS on the same 2012 R2 server and now you want to migrate these roles to one 2019 server.
I mainly focus on the questions or issues about AD DS.
For migrating AD DS role and AD-integrated DNS from 2012 R2 to 2019, here are my suggestions for your reference.
Firstly, the two prerequisites to introducing the first 2019 or 2022 domain controller are that domain functional level needs to be 2008 or higher and older sysvol FRS replication needs to have been migrated to DFSR
1.Check every DC is working fine (run Dcdiag /v on each DC, maybe you have only one DC).
2.Check AD replication is working fine (run repadmin /showrepl and repadmin /replsum on primary DC, if there is only one DC, then you do not need to check it).
3.Had better back up DC using built-in Windows backup role on DC.
1.Create new VM in HyperV and Install 2019, set TCP/IP, server name and preferred DNS server and add it to domain.
2.Add AD DS role and DNS role on new 2019 server.
3.Promote new 2019 server as a DC (also DNS and GC).
4.Check DC health one by one and AD replication status.
5.Move FSMO roles(five fsmo roles) from old 2012 R2 DC to new 2019 DC server.
6.Check if FSMO roles(five fsmo roles) is actually on new server.
7.Demote the old DC and remove it from the domain (maybe turn off this old DC or change its IP address to another one IP address and change server name to another one name) and configure the IP address and name of the new server to match the old server and turn off the old server. Reboot the new DC (if you have only one DC in the domain, we did not recommend you change IP address and name of the new server to old one).
8.Raise the domain and forest functional levels if needed.
9.Verify the migration.
Also, consider the following:
If the removed DC was a DNS server, update the DNS client configuration on all member workstations, member servers, and other DCs that might have used this DNS server for name resolution. If it is required, modify the DHCP scope to reflect the removal of the DNS server.
If the removed DC was a DNS server, update the Forwarder settings and the Delegation settings on any other DNS servers that might have pointed to the removed DC for name resolution.
Tip: For other roles migration, I suggest you post different new threads with different tags before you start your any migration on this server.
1.Migrate File server with file storage tag.
2.Migrate DHCP server with DHCP tag.
Hope the information above is helpful. If you have any question or concern, please feel free to let us know.
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