well I could not export and import configs from 7.1.5 to 8.6.2 because of a huge amount of errors.
now I try to understand how I can upgrade my test CUCM 7.1.5 to 8.6.2
I tried to start the VM with 7.1.5 from the connected virtual DVD with bootable 8.6.2.
but it asks "do you want to rewrite the disk?"
and it's not what I want to do.
what is the right way of uprgrading from 7.1.5 to 8.6.2?