Hi @Paul Smith ,
For security reasons, we recommend that you do not install SQL Server on a domain controller. SQL Server Setup will not block installation on a computer that is a domain controller, but the following limitations apply:
• You cannot run SQL Server services on a domain controller under a local service account.
• After SQL Server is installed on a computer, you cannot change the computer from a domain member to a domain controller. You must uninstall SQL Server before you change the host computer to a domain controller.
• After SQL Server is installed on a computer, you cannot change the computer from a domain controller to a domain member. You must uninstall SQL Server before you change the host computer to a domain member.
• SQL Server failover cluster instances are not supported where cluster nodes are domain controllers.
• SQL Server is not supported on a read-only domain controller. SQL Server Setup cannot create security groups or provision SQL Server service accounts on a read-only domain controller. In this scenario, Setup will fail.
• A SQL Server failover cluster instance is not supported in an environment where only a read-only domain controller is accessible.
Refer to MS document SQL Server 2019: Hardware and software requirements.
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