Azure AD Connect on Server 2019 Core (no GUI)

Question

I've just installed Azure AD Connect on my first domain controller and it installed and configured with no problems and is now syncing on-prem AD with Azure.

I tried to install in on the second DC, the only difference between the two machines is that this one did not have the GUI installed. No problem, ran the installer from the command line. Once the installer finishes and the configuration screens start, it crashes as soon as I click [Customize].

XamlParseExeption - Provide value on 'System.Windows.Baml2006.TypeConverterMarkupExtension' threw an exception.

I've done some searching and found some comments that lead me to believe this is not supported on Server Core. That seems foolish. I can manage the server remotely for everything so going Core makes a lot of sense. Remote management with Powershell is the new hotness....right?

Do I really need the GUI to install this? Once it's running, can I uninstall the GUI? Seems even more foolish if true. Is there a Powershell method to install this product?

Answer 1

This is outlined on Prerequisites for Azure AD Connect.

Namely, it does not support Server Core. It is also not recommended to deploy on Domain Controller(s). Another thing to keep in mind is AAD Connect is not a highly available service; you technically don't need to install a second one if you're doing PHS/federation.

Answer 2

As @trevorseward starts to explain - Azure AD Connect is not designed to work on Windows Server Core version - plus, this scenario will not be supported by Microsoft for production environment. As described on the following page : https://learn.microsoft.com/fr-fr/azure/active-directory/hybrid/how-to-connect-install-prerequisites.

Concerning Azure AD Connect, it's also not supported to have several Azure AD Connect for 1 Tenant / Azure Active Directory. Azure AD Connect is not really a SPOF but if you want to setup high-availability for this component - you may deploy 1 production and working Azure AD Connect + 1 another Azure AD Connect that will be configured in Staging mode. More details on this link part Staging server.