You want to verify that an application partition is instantiated on a replica server. After you add a domain controller as a replica server for an application partition, the data in the application partition needs to fully replicate to that domain controller before it can be used on that domain controller.
Use the following command to determine if there are any problems with application partitions on a domain controller:
> dcdiag /test:checksdrefdom /test:verifyreplicas /test:crossrefvalidation /s:[RETURN] <DomainControllerName>
The dcdiag CheckDSRefDom, VerifyReplicas, and CrossRefValidation tests can help determine if an application partition has been instantiated on a server and if there are any problems with it. Here is the dcdiag help information for those three tests:
This test looks for cross-referencess that are in some way invalid.
This test checks that all application directory partitions have appropriate security descriptor reference domains.
This test verifies that all application directory partitions are fully instantiated on all replica servers.
Another way you can check to see if a certain application partition has been instantiated on a domain controller yet is to look at the msDS-HasInstantiatedNCs attribute for the server's nTDSDSA object. That attribute has DN with Binary syntax and contains a list of all the application partitions that have been successfully instantiated on the server. Unfortunately, tools such as ADSI Edit and dsquery do not interpret DN with Binary attributes correctly, but it can be viewed with LDP.