In addition to these differences, it's also important to understand the various Flexible Single Master Operations (FSMO) roles in Active Directory that a domain controller can hold.
While Active Directory is a distributed system, some servers only carry out specific roles. If something happens to this server or you need a more substantial server to handle a particular role, you must know which servers are handling each role.
There are five FSMO roles:
- PDC emulator (one per domain): This role allows Windows Server 2003 to act as a Windows NT primary domain controller (PDC), and it provides replication support for Windows NT-based backup domain controllers (BDCs). In addition, this role assists with time and group policy synchronization.
- Infrastructure master (one per domain): This role is responsible for updating the group-to-user references whenever the members of groups change or receive new names.
- Relative ID (RID) master (one per domain): This role ensures that every object created has a unique identification number.
- Schema master (one per forest): This role is responsible for maintaining and modifying the Active Directory schema.
- Domain naming master (one per forest): This role is responsible for the addition and deletion of domains in a forest.
How can you determine which servers hold these roles in an Active Directory forest? To find the PDC emulator, the infrastructure master, and the RID master, follow these steps:
- Go to Start | Administrative Tools | Active Directory Users And Computers.
- Right-click the domain, and select Operations Master.
The resulting three tabs will show you which server holds each respective role.
To find the schema master, follow these steps:
- Go to Start | Run.
- Enter regsvr32 schmmgmt.dll in the Open text box, and click OK.
- Go to Start | Run.
- Enter mmc in the Open text box, and click OK.
- Go to File | Add/Remove Snap-In, and click Add.
- Click Active Directory Schema, click Add, click Close, and click OK.
- Right-click Active Directory Schema, and select Operations Master from the shortcut menu.
To find the domain naming master, follow these steps:
- Go to Start | Administrative Tools | Active Directory Domains And Trusts.
- Right-click Active Directory Domains And Trusts, and select Operations Master from the list.
Each option features a Change button, which allows you to move the role to another domain controller.