The functioning and performance of a domain controller is highly dependent on replica placement. If you have less than 20 domain controllers, you should place the copy of the configuration and schema partition replicas local to the domain controller to improve the login performance. This is because the configuration and schema details are often queried for by DSfW services. Follow the partition and replication guidelines given below:
You must have replicas of all partitions inside the DSfW domain boundary local to the respective domain controllers.
Do not remove the replica of the domain's primary eDirectory partition from its respective domain controller, to avoid exhaustion of the Domain RID Pool.
Do not merge the eDirectory partition that is mapped as the first partition of a DSfW domain.
Do not partition DSfW default containers such as OU=OESSystemObjects, CN=Computers, OU=Domain Controllers. Partitioning default containers will lead to critical DSfW service issues.
Do not merge a configuration or schema partition that is created by the DSfW provisioning wizard.
Always use the domaincntrl tool to add or remove additional partitions to domain after provisioning the server.