DFS Site Information Is Not Updated When You Move Server to a New Active Directory Site

After you move a server that is a replica member of a Domain Distributed File System (DFS), client computers that connect through the DFS namespace seem to disregard the relocation of a server to a different Active Directory site.

This behavior occurs because the DFS site information is not updated when you relocate the server, which is referred to in a Domain DFS root or link, to a new Active Directory site. The site information for a computer that you add to Domain DFS roots and links is hard coded to the site to which it belonged when you added the computer to a domain DFS replica.

To resolve this behavior, update the site information by removing the server as a root or link replica, and then by adding it back as a root or link replica. This action causes DFS to read the server's new site information, and to hand out referrals correctly. Please refer to the "More Information" section of this article for additional information.

Microsoft has confirmed this to be a problem in Microsoft Windows 2000.

If you use the Distributed File System console (Dfsgui.msc) to remove the server from DFS and add it back, and if you use FRS for replication, FRS must resynchronize all data on the modified computer. To avoid the resynchronization, use the DFS command-line tools to remove the server and add it back into the DFS namespace.

Verifying Site Information for DFS Targets

Use the dfsutil /view command from the \Support\Tools folder of the Windows Server CD to display site information for computers that are referred by Domain DFS roots and targets (type dfsutil /? for syntax). For example, to view the site information for the domain DFS \\Corp.com\DFSFT, the syntax is: At this point, update the site information for any computers that appear in the incorrect Active Directory site.

Updating Site Information for DFS Targets

To update the site information for a Replica member (\\Member\Share), remove and then re-add the replica member:

1. Use the following command to remove the replica member from a link in the DFS namespace:
   Dfscmd /remove \\Domain\DfsName\LinkName \\Member\Share
2. Use the following command to add the replica member back to a link in the DFS namespace:
   Dfscmd /Add \\Domain\DfsName\LinkName \\Member\Share

To update the site information for a Replica member (\\RootSrv\RootShare) from a root in the DFS namespace, and then to re-add it:

1. Use the following command to remove the replica member from a DFS Root in the DFS namespace:
   Dfsutil /Remroot: DfsName /Server:RootSrv /Share:RootShare
   
   Note: Based on the sample in the "Verifying Site Information for DFS Targets" section of this article, the DfsName variable would be DFSFT. This is case sensitive; use the same case information as was displayed.
2. Use the following command to add the replica member back to a DFS root in the DFS namespace:
   Dfsutil /Addroot:DfsName /Server:RootSrv /Share:RootShare

Note: Do not use the Remroot option when the Replica member that you are removing as root is the only root replica for the DFS namespace because doing so removes the entire DFS namespace.

The DFS configuration data for Domain DFS is stored in a binary large object (BLOB) format in Active Directory.

When you add a computer to Domain DFS, DFS reads the target servers site information and writes it to the DFS BLOB.

Site information for computers that participate in a Domain DFS is hard coded in the DFS BLOB structure and it is not updated if you move the computer to a subnet that corresponds to a different Active Directory site; therefore site information is incorrect.

Sample Scenario

The following example is based on the premise that you are adding a computer, \\Server1, to a Domain DFS \\corp.com\dfsft in site A and then you move it to site B:

1. DFS site aware clients in site A see \\Server1 as being in the site A portion of the referral list, even though it is in a different Active Directory site.
2. Clients in site B that are expecting to connect to the DFS target in the same site only do so if there are other targets in the same Active Directory site, otherwise it randomly selects a server.