The recommended way to upgrade a domain is to promote new servers to DCs that run a newer version of Windows Server and demote the older DCs as needed. This method is preferable to upgrading the operating system of an existing DC, which is also known as an in-place upgrade.
Follow these general steps before you promote a server to a DC that runs a newer version of Windows Server:
Verify the target server meets the system requirements.
Verify application compatibility.
Review recommendations for moving to a newer version of Windows Server.
Verify security settings.
Check connectivity to the target server from the computer where you plan to run the installation.
Check for availability of the necessary Flexible Single Master Operation (FSMO) roles in Active Directory. This step is required for the following scenarios:
To install the first DC that runs the latest Windows Server version in an existing domain and forest, the machine where you run the installation needs connectivity to:
The schema master to run adprep /forestprep.
The infrastructure master to run adprep /domainprep.
To install the first DC in a domain where the forest schema is already extended, you only need connectivity to the infrastructure master.
To install or remove a domain in an existing forest, you need connectivity to the domain naming master.
Any DC installation also requires connectivity to the RID master.
If you're installing the first read-only DC in an existing forest, you need connectivity to the infrastructure master for each application directory partition, which is also known as a non-domain naming context.
To find out which server or servers hold which FSMO role, run the following commands in an elevated PowerShell session by using an account that's a member of the Domain Admins group:
PowerShell
Copy
Get-ADDomain | FL InfrastructureMaster, RIDMaster, PDCEmulator
Get-ADForest | FL DomainNamingMaster, SchemaMaster
Greeting,
Rachel Gomez
