Forum Discussion
Moving to different hardware and upgarding from Windows server 2012 to 2016
The prerequisite before introducing the first 2016 domain controller: domain functional level needs to be 2003 or higher
The two prerequisites to introducing the first 2019 domain controller are that domain functional level needs to be 2008 or higher and older sysvol FRS replication needs to have been migrated to DFSR
https://techcommunity.microsoft.com/t5/Storage-at-Microsoft/Streamlined-Migration-of-FRS-to-DFSR-SYSVOL/ba-p/425405I'd use dcdiag / repadmin tools to verify health correcting all errors found before starting any operations. Then stand up the new 2016, patch it fully, license it, join existing domain, add active directory domain services, promote it also making it a GC (recommended), transfer FSMO roles over (optional), transfer pdc emulator role (optional), use dcdiag / repadmin tools to again verify health, when all is good you can decommission / demote old one, and move on to next one.
The prerequisite before introducing the first 2016 domain controller: domain functional level needs to be 2003 or higher
The two prerequisites to introducing the first 2019 domain controller are that domain functional level needs to be 2008 or higher and older sysvol FRS replication needs to have been migrated to DFSR
https://techcommunity.microsoft.com/t5/Storage-at-Microsoft/Streamlined-Migration-of-FRS-to-DFSR-SYSVOL/ba-p/425405
I'd use dcdiag / repadmin tools to verify health correcting all errors found before starting any operations. Then stand up the new 2016, patch it fully, license it, join existing domain, add active directory domain services, promote it also making it a GC (recommended), transfer FSMO roles over (optional), transfer pdc emulator role (optional), use dcdiag / repadmin tools to again verify health, when all is good you can decommission / demote old one, and move on to next one.