Article ID: 248717 - View products that this article applies to.
This article was previously published under Q248717
The Global Catalog (GC) contains a partial replica of every object in the enterprise. This article discusses how to manipulate the attributes which make up the set values replicated to the GC. Deciding which attributes will replicate (in addition to the default attributes) requires careful planning with consideration for network traffic and necessary disk space.
Before describing how to set an attribute to replicate in the GC, it is important to note the effects this has on network replication traffic.
After an attributeSchema object is created, marking an additional attribute to replicate to the GC causes a full replication (also known as a "full sync") of all objects to the GC as described below. This behavior occurs on the versions of Windows 2000 listed in this article.
Every server has a full and write-able copy of its own domain. If that server is also a GC, the remaining domains in the forest are held as read-only, partial copies. "Partial" means that only a subset of the attributes is kept.
When an attribute is added to the GC, it is added to the partial copy subset (partial attribute set). This causes the GC to perform a "full sync" of all the read-only copies again to repopulate itself with only the partial attributes that it needs to hold. This full sync occurs even if the attribute property isMemberOfPartialAttributeSet is set to "True." Thus, it only does a full sync on the read-only partial copy domains and not its own write-able domain, the configuration directory partition or schema directory partition.
"Directory partition" has been previous referred to as "naming context." Removals from the GC are handled locally without replication.
In order to modify the attributes that replicate to the Active Directory GC, you must modify the schema. To modify the schema, an administrator must be made a member of the "Schema Admins" group. In addition to being a member of this group, a registry key must be set on the Schema master. For additional information about this process, click the article number below to view the article in the Microsoft Knowledge Base:
216060This article also describes steps that are performed in the Active Directory Schema Microsoft Management Console (MMC). You can acquire this snap-in through a full installation of the Windows 2000 Administration Tools or by registering Schmmgmt.dll in the system root on a Windows 2000 server.
(http://support.microsoft.com/kb/216060/EN-US/ )Registry Modification Required to Allow Writing to Schema
To activate the Schema MMC snap-in follow these steps:
To Make Modifications Using Active Directory Schema MMC Snap-In
Could not change whether this attribute should be replicated to the global catalog servers.
To Make Modifications Using ADSI ScriptsActive Directory Services Interfaces (ADSI) can make modifications to the schema through its Lightweight Directory Access Protocol (LDAP) provider. The code below determines the location of the schema, bind to the attribute in the schema, and make the necessary changes to force it to replicate to the GC.
If the above registry change is not made, the following error occurs when attempting to run the script:
Error -2147016651 (80072035): Automation error. The server is unwilling to process the request.
For additional information, click the article numbers below to view the articles in the Microsoft Knowledge Base:
(http://support.microsoft.com/kb/232517/EN-US/ )Global Catalog Attributes and Replication Properties
230663For additional information about ADSI, see the following Microsoft Web site:
(http://support.microsoft.com/kb/230663/EN-US/ )How to Enumerate Attributes Replicated to the Global Catalog
Article ID: 248717 - Last Review: September 28, 2007 - Revision: 3.4