Hello,
Thank you for posting here!
In addition to domain functional level in the above helpful replies.
Your Domain Functional Level (DFL) must be set to Windows Server 2008 or higher i.e. no Windows Server 2003 or older domain controllers
The requirements before we take our first step to this beautiful replication engine, well, we can see other requirements here:
- Your Active Directory must be in a healthy state i.e. no issues regarding Active Directory replication between all domain controllers.
- Your SYSVOL must be healthy as well i.e. no Journal Wraps on any domain controllers and healthy replication of SYSVOL.
- It is preferred to do the migration on PDC Emulator as it is the authority on SYSVOL, though any domain controller in your domain could be used which will attempt to contact PDCe every time and replication will take care of all the steps.
- Each domain in your environment would need the same steps to migrate to DFSR. SYSVOL is domain based and hence all the above requirements apply to each domain that you plan to migrate to DFSR.
For more information about migration prerequisite and migration steps, we can refer to the article.
qUICKLY Explained: Migrate Your SYSVOL Replication from FRS to DFSR
https://learn.microsoft.com/en-us/archive/blogs/qzaidi/quickly-explained-migrate-your-sysvol-replication-from-frs-to-dfsr