How to Roll Back Functional Level after upgrade? We are upgrading our AD from Windows 2003 to Windows 2012 R2 AD. My question is just incase we run into issues with our upgrade and we need to roll back Domain Functional Level and Forest Functional Level what step we should take? I hear it is irreversible but any steps we should take just in case we need too.
Maybe systemstate backup? or shut down one DC down before raising the DFL/FFL? not sure if anyone did this successfully.