If you have any battle-worn domain controllers that have been upgraded multiple times, your domain is probably still running the outdated replication engine, File Replication Service (FRS), which dates back to Server 2000 and 2003. I am not sure why Microsoft doesn’t publicize this as much as upgrading to the latest OS, because it is just as important.
If you have domain controllers that are 2008 or newer, you absolutely should migrate to DFSR today. As it was designed in a bygone era, domains will often have replication errors or poor performance when using FRS in today’s demanding environments. Follow these steps to migrate to DFSR.
- All DCs must be at least Server 2008
- Domain Functional Level must be at least Server 2008
- Active Directory services must be in good general health
- Active Directory replication must be fully functioning
I would also suggest performing this migration after hours to minimize potential impact to users on the network. Ensure you have valid backup of all DCs before starting.
Note: perform this operation on your Primary Domain Controller (PDC)
There are 4 main stable states during this migration and you must wait for each to finish before moving on or you could cause yourself some serious problems.
- State 0 – Start
- State 1 – Prepared
- State 2 – Redirected
- State 3 – Eliminated
Open an elevated Powershell session on your PDC, run this command to go from Start through Prepared State.
dfsrmig /setglobalstate 1
After running the previous command, wait for about 10 minutes or so then run the following command to see where you are at. Wait until you get a message that all domain controllers have reached a consistent state.
Once you are in Prepared State run this command.
dfsrmig /setglobalstate 2
Again, wait for about 10 minutes or so then run the following command to see the migration status. Wait until you get a message that all domain controller have reached a consistent Redirected state.
Once the operation is complete, you should open all of you domain controllers and check that you can navigate to the SYSVOL and it is the Redirected State. It is usually found here: C:\Windows\SYSVOL\sysvol\yourdomain.com
You need to check this because the last phase, getting to Eliminated State, cannot be undone and could cause some undue sadness if you didn’t reach Redirected. When ready run this command.
dfsrmig /setglobalstate 3
Check status again with this command.
Final Eliminated State message.
After your reach Eliminated State you may get this error popup, do not be alarmed. This is telling you that the old SYSVOL is gone because it has been “Eliminated.” The new folder is called SYSVOL_DFSR, located here: C:\Windows\SYSVOL_DFSR\sysvol\yourdomain.com
You might also want to check that the FRS service is completed stopped and disabled on every DC. Open up services.msc and find File Replication Service, verify it has been disabled.
If it hasn’t been disabled open the service object and manually disable it.
You should be good to go at this point.