Installing SQL Server on a domain controller is a topic that often comes up in discussions and interviews. In this blog post, we will explore the concept of installing SQL Server on a domain controller and discuss the implications and recommendations provided by Microsoft.

Q1. Can I install SQL Server on a domain controller?

Answer: There is no restriction in the SQL Server setup that would block the installation of SQL Server on a domain controller. Therefore, it is possible to install SQL Server on a domain controller.

Q2. What does the warning during SQL Server setup mean?

Answer: SQL Server is an enterprise-level server that can put a significant load on the machine in terms of CPU, memory, and IO. On the other hand, a domain controller is responsible for various authentication-related activities. Installing SQL Server on a domain controller can potentially impact the performance of the domain controller and cause issues with logon to the domain. While it is technically possible to install SQL Server on a domain controller, Microsoft does not recommend it.

Q3. Can I install SQL Server on a Read-only domain controller (RODC)?

Answer: Microsoft does not support installing SQL Server on a Read-only domain controller (RODC). This means that even if you manage to install SQL Server on an RODC, Microsoft’s support team will not assist in fixing any issues that may arise.

Q4. Can I install SQL Server and then promote the server to a domain controller?

Answer: It is advisable to uninstall SQL Server before promoting the server to a domain controller. Once the server has been promoted, you can then install SQL Server again. This ensures a clean installation and avoids any potential conflicts or issues.

Q5. Which account should I use to run SQL Server Service on a domain controller?

Answer: On a domain controller, you cannot run SQL Server services under a LocalService account, NetworkService account, or Service SID (such as NT Service\MSSQLServer). The only option left is to use the LocalSystem account.

It is important to note that while it is technically possible to install SQL Server on a domain controller, it is not recommended by Microsoft due to potential performance and compatibility issues. It is always best to separate the roles of a domain controller and a SQL Server to ensure optimal performance and stability.

Thank you for reading this blog post. We hope it has provided you with valuable insights into the topic of installing SQL Server on a domain controller.