I got asked the following question at work lately.
The team has a test server running 2012 on bare metal and a few Hyper-V guests. This would make an ideal test for DR to Azure but this requires the host be running 2012R2 (using Azure backup without SCVMM).
Can you upgrade the host without disturbing the guests or do you have to save the VHD's for each guest and after the host has been upgraded, create new VM's and re-attach the VHD's?
Thaks