Domain functional level update

BCTech 21 Reputation points
2023-06-25T14:20:01.8633333+00:00

I am upgrading a network from Windows 2008 AD to Windows 2019 Domain Controller. I am going to add the Windows 2019 as a second redundant domain controller, move services from Windows 2008 to Windows 2019 server (DNS, FSMO roles, etc..) and then decommission the Windows 2008 server.

One hiccup is that the Windows 2008 server is using an older replication version (FRS) AND is at a domain functionality level of Windows 2000.

When I went to confirm the replication version of the server, I received the output via DFS Mig command:

"The current domain functional level is not Windows Server 2008 or abo e. DFSMig is only supported on Windows Server 2008 or above level domains."

So what I "believe" I have to do is first update the functional level on the Windows 2008 server to 2008 functional level, and then proceed with the migration process. I am looking for MS documentation explicitly stating that is what is required, but can't find that. Was wonder if any one can point me to that or confirm my process (these are general steps with more sub steps):

Run DCDiag Health Checks

Update Windows 2008 DC to Windows 2008 Domain and Forest functional level

Migrate from FRS to DFRS on Windows 2008 Server

Join Windows Server 2019 to the domain

Prepare AD for Server 2019 DC

Promote Server 2019 as ADC

Check Replication between both DC's

Transfer FSMO roles to the Server 2019

Remove AD Servers from 2008 R2

Active Directory
Active Directory
A set of directory-based technologies included in Windows Server.
6,151 questions
Windows Server Migration
Windows Server Migration
Windows Server: A family of Microsoft server operating systems that support enterprise-level management, data storage, applications, and communications.Migration: The process of making existing applications and data work on a different computer or operating system.
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  1. Dave Patrick 426.4K Reputation points MVP
    2023-06-26T12:59:00.56+00:00

    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

    I'd use dcdiag / repadmin tools to verify health correcting all errors found before starting any operations. Then stand up the new 2019 or 2022, patch it fully, license it, join existing domain, add active directory domain services, promote it also making it a GC (recommended), transfer FSMO roles over (optional), transfer pdc emulator role (optional), use dcdiag / repadmin tools to again verify health, when all is good you can decommission / demote old one.

    --please don't forget to upvote and Accept as answer if the reply is helpful--