Domain Controllers Responding to Requests

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Active Directory Domain Services requires that certain domain operations reside on a single domain controller in the domain or forest. The requirement prevents conflicts that might be introduced while an operation master is offline. These operations are accomplished by Operations Master roles. The Active Directory Installation Wizard (Dcpromo.exe) defines five Operations Master roles, all of which are used in the Windows EBS environment:

  • Schema master

  • Domain naming master

  • Relative Identifier (RID) master

  • Primary Domain Controller (PDC) emulator

  • Infrastructure master

Each of these roles must be available in the same Active Directory site when dependent activities take place in the domain and to make changes that are associated with that role. All of the Operations Master roles can reside on a single server, or individual roles or combinations of roles can exist on different servers in the same Active Directory site.

During installation, the Windows EBS Installation Wizard determines whether these roles exist in your local Active Directory site, before transferring the roles to the servers running Windows EBS. If the roles do not exist, you are prompted to verify that existing domain controllers that could contain those roles are running and are connected to the network. If the roles are detected, they are transferred.

In some situations, a server that originally contained one or more of the Operations Master roles may no longer exist. In these cases, the Installation Wizard prompts you to confirm that these roles can be "seized." This means that the role is installed on the appropriate server running Windows EBS without transferring existing domain or forest data from an existing Operations Master role. However, if the server that contains the original role is brought back online, conflicts will occur. Be certain that this condition cannot occur before you seize unavailable roles.

For additional information about Operations Master roles in Windows Server 2003, see the Microsoft Web site (https://go.microsoft.com/fwlink/?LinkId=93375).