Windows Server Backup doesn’t work on 2012 R2. In various setups, which you can read by seaching Google, it fails over and over again with vague error messages. Essentially, the backup software is buggy and should never have been released in it’s current state so if you’re trying to take full images of your servers you’ll need to use something better.

I have used StorageCraft’s ShadowProtect on my VMs successfully for over a year now and while the licensing is going to cost you upwards of £1000 for a sizeable server room it is well worth the cost.