Should I install AD DS by using the regular dcpromo routine or IFM?
Another way to reduce replication overhead in the forest recovery process is to rebuild domain controllers by using Install from Media (IFM). IFM is an option that allows you to use media as an AD DS installation source instead of replicating all AD DS data over the network. You can create the installation media by using either of the following methods: Run the ntdsutil ifm command on a domain controller that runs Windows Server 2008. For more information about running the ntdsutil ifm command, see Installing Active Directory Domain Services from Media (http://go.microsoft.com/fwlink/?LinkId=132630). Back up the source domain controller to a removable medium, ship the backup to the location, and restore the backup on the target computer. Then, you can source the partitions from the installation medium by running the dcpromo /adv command or by specifying the location of the installation media on the Install From Media page in the Active Directory Domain Services Installation Wizard. You