I've walked into a new client that needs to upgrade their schema from 2003 to 2008. Their system is 90% virtual servers but they only have 1 domain controller. At this point, should I go ahead and add the 2nd domain controller, then upgrade or upgrade the schema with the one domain controller then add the backup domain controller. I know a forest full backup is needed either way. Thanks for your help.

• Edited by Zarrr 8 hours 59 minutes ago

I don't see any reason to not go ahead and add the 2008 R2 server to domain, patch it fully, dcpromo it and moves the roles over. In the end you'll want to end up with at least two DCs for redundancy. You can follow along here.

http://blogs.msmvps.com/mweber/2010/02/10/upgrading-an-active-directory-domain-from-windows-server-2003-to-windows-server-2008-or-windows-server-2008-r2/