Thanks so much for the instructions, a very big help to a novice like myself. I now need to setup a Backup Domain Controller.

I am assuming that for redundancy sake, I will need to bring up an additional Ubuntu box with DNS (slave zone?), Openldap (how to setup replication?) and Samba (how to configure?).

Is there an order that I should tackle these or any good documentation that I can dig into that will help me with this? Any advice will be much appreciated.