I've read through other people's Q&A about upgrading from Windows Server 2008R2 to 2012R2 and seem to have the basic upgrade process down. My unique situation deals with Update Sequence Numbers not matching on our two domain controllers. I made the mistake of creating a vSphere snapshot on a DC and restoring it a while back. I found out later that is a no-no but, it was too late.
My question is - do I have to fix the USN mismatch problem before attempting to do an across the wire DC upgrade on two new server VMs?