We purchased a Brand new 2012 Server from Dell for the express purpose of making it a "cold spare" backup for our existing 2008R2 DC. which is a fairly simple Active Directory for our 25 users with no special functionality or Apps, just some shared folders for docs.
In the past I would call this a BDC ( Backup Domain Controller) but I understand its now just called a second DC.
The trick is that the new 2012 Server is now physically located 200 miles away in my small branch office but luckily they are connected with a pair of SonicWall TZ210s with a strong Site to Site VPN running 24/7 as I am building it up and adding files etc,
If I make it a DC and since its much newer I am concerned that my 25 users, 200 miles away will then be looking for it to authenticate every morning. So if I take it off line for a week they probably will just go back to the 2008 server, is that the right way to look at it?
Or should I really just forget about the "Cold spare" idea and just consider it a second DC that happens to be across a VPN ?
Comments, gotchas, recommendations would be most appreciated