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Server Migration: Upgrading Server Boxes on PDC & BDC

gguerra3 asked
Last Modified: 2010-04-18
I am upgrading two servers to newer faster boxes.. One is the Primary Domain Controller (PDC) and another is a Backup Domain Controller (BDC)
Should I demote the BDC to a stand alone server, build the new box as a standalone, then promote back to a BDC?? is this the proper way?
As for the PDC, I will build it up from scratch as a standalone and when I'm ready to make the switch I want to make it a PDC, what is the easiest way to transfer AD content (user, computers etc?) to the new box.
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Hypercat (Deb)President

In Windows 2003 domains, there is no such thing as a PDC or BDC.  All you need to do is build the new server and install it as a standalone server on the domain. Make sure that if it is replacing a server that is running network services such as DNS, DHCP, etc., these services are installed on the new server also.  Then, promote the new server to DC and allow enough time for AD to replicate completely.  On a small network, AD replication is pretty much immediate.  If you have a larger network spread out over multiples locations, then use replmon to make sure replication is completed on the new DC before doing anything else.  

After AD replication is complete on the new server, transfer any FSMO roles from the server you are removing to the new server.  Also, be sure to make the new server a global catalog server if it replacing a server that was a GC.  Then, demote the old DC that you are going to remove from the domain to standalone server.  Again, make sure replication of this change is complete before actually shutting the server down and removing the computer account from AD.

The only circumstances under which you would want to do this differently is if you have to use the same name for the new DC as the old one.  This is generally not a good idea, but sometimes it's unavoidable.  If that's the case, you have to transfer all of the FSMO roles from the DC you are going to remove to the other DC FIRST before you do anything else.  Then, you can demote and remove the old DC from the network (again, make sure replication is complete before shutting it down and deleting the computer account from AD).  Then, once the old server has been completely removed from AD, you can install and configure the new server using the same name as the old one, promote it to DC, transfer the FSMO roles back, etc.

Toni UranjekConsultant/Trainer

OK, if you have W2K3 servers, there are no PDCs and BDCs. Usually there is a domain controller called First DC in eacghforest which is holding all FSMO roles (Schema, Domain Naming, RID, Infrastructure Master and PDC emulator).

New servers should be joined to domain as member servers, than promoted to DC as replica DCs, and all FSMO roles should be transfered to one of the new servers. Later, old servers should be demoted.

Additional reading: http://support.microsoft.com/kb/32480 and http://support.microsoft.com/kb/255690


Well, I got a confession to make.. I'm actually using Server 2000, and since there was no section for it I posted here.. and yes the new server will have he same name as the BDC (in this case). What I think I will do is install the new server as stand alone, shut down the old server, rename the new server to match the old server name and promote it to DC and let it propagate..

This leaves the PDC (or master) which I plan on replacing also..

What plan could I take on this one??

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