RODC(READONLY DOMAIN CONTROLLER)http://mynetworkplanet.blogspot.com/2009/07/installation-of-read-only-domain.html
sabyasachi
which the installation is completed in two stages
* The first stage of the installation, which requires domain
administrative credentials, creates an account for the RODC in AD DS.
* The second stage of the installation attaches the actual server
that will be the RODC in a remote location, such as a branch office,
to the account that was previously created for it. You can delegate
the ability to attach the server to a nonadministrative group or user,
which is a feature I find pretty neat from the deployment perspective.
During this first stage, the wizard records all data about the RODC
that will be stored in the distributed Active Directory database, such
as its domain controller account name and the site in which it will be
placed. This stage must be performed by a member of the Domain Admins
group. The administrator who creates the RODC account can also specify
at that time which users or groups can complete the next stage of the
installation.
http://mynetworkplanet.blogspot.com/2009/07/installation-of-read-only-domain.html
The next stage of the installation can be performed in the branch
office by any user or group who was delegated the right to complete
the installation when the account was created. This stage does not
require any membership in built-in groups, such as the Domain Admins
group. If the user who creates the RODC account does not specify any
delegate to complete the installation (and administer the RODC), only
a member of the Domain Admins or Enterprise Admins groups can complete
the installation.
During the second stage, the wizard installs AD DS on the server that
will become the RODC and attaches the server to the domain account
that was previously created for it. This stage typically occurs in the
branch office where the RODC is deployed. During this stage, all AD DS
data that resides locally, such as the database, log files, and so on,
is created on the RODC itself.
At this point of the installation process, we can specify any group or
user who will later be able to install and manage the RODC. As we are
not in such deployment scenario, we leave the field empty:
Chose Group / user or you can do it after installation