First, a big thank you to @scipio_americanus for writing this up. It seems there are many roads to travel to integrate AD and OMV but, all lead to a dead-end. This seemed so clear-cut and being new I thought was going to work but, alas I've hit another dead-end.
I don't suppose someone could tell me how to troubleshoot step 2 - the joining domain part. This is what I get:
My domain controller is a Windows Server 2008 R2 (fully patched).
Any help will be greatly appreciated!!