Scenario:
Platform : Windows 2012 R2 Single forest -Single domain having 20 Domain Controllers and trust is in place with couple of different organization Domains and Forests. Root DC and other DCs are windows 2012R2 only for our domain. All DCs are AD-Integrated DNS.
Requirement: Plan to provision 4 nos of Windows2016 DCs and decommission all other existing 2012R2 DCs. What are steps to follow to complete this entire activity.
Our Plan: Add all 4 servers with O/S 2016 one by one within current domain and promote them as DCs individually. Transfer the FSMO roll to identified newly promoted 2016 DC. Check DC replication after validating site replication. Then keep this hybrid mode for 4-5 days and check for any issues then decommission 2012 R2 Dcs one by one. Old Root DC will be decommissioned at last.
As this is very critical activity, we need some expert suggesstion and thus any suggestions would be highly appreciated.
Regards,
SoumenG