DCPromo using Install From Media (IFM)
Initial replication can take a while when promoting a domain controller to an existing domain. This is especially true for domains containing a large number of Active Directory objects. In large-size enterprises we have seen the DCPromo process take upwards of two hours to complete even on fast network links. Not to mention remote/satellite/field sites with a slow WAN link. For such scenarios it may be valuable to perform DCPromo using Install From Media (IFM). Here is a quick how-to on performing a DCPromo using Install From Media (IFM). There are many posts on this out there, but this is a condensed version for quick reference.
How to perform DCPromo using IFM
1. Open command prompt on an existing domain controller and run the following.
ntdsutil activate instance ntds ifm create full c:\ifm
2. Copy the resultant IFM folder to the server on which the DCPromo is being performed.
3. In the DCPromo wizard select install from media, specifying the path to the ifm folder.
There you have it! Your next domain controller promotion should complete a lot faster using Install From Media (IFM).