On DC
1. cmd> ntdsutil.ext
2. Activate instance ntds
3. ifm
4. create sysvol full c:\ifm
5. make sure share the IFM folder
On New RODC
1. copy ifm folder from share server in which DC
1. Install ADDS
2. Promote domain controller
3. Add a domain controller to an existing domain
4. Install from media (c:\ifm)
