XADM: Function and Effects of Running the DS/IS Consistency Adjuster

This article explains the function and effects of running DS/IS consistency adjuster. Because of the potential problems that the DS/IS consistency adjuster may cause, Microsoft recommendeds that you contact Microsoft Product Support Services (PSS) before you run it.

The DS/IS consistency adjuster is used in disaster recovery scenarios where it is not possible to restore the directory to the recovery computer, or where the information store (the Priv.edb or Pub.edb file) is copied to a recovery computer with a name that is different from that of the original server.

The DS/IS consistency adjuster is run to re-create the directory objects for the mailboxes and for public folders that are in the store and not in the directory. This process also resets the Home-MDB attribute on all public folders in the hierarchy that are homed on unknown sites or servers. In addition, the process strips the public folder access control lists (ACLs) of any invalid entries (that is, users who do not exist in the current directory). Servers and sites are "unknown" and invalid entries exist when replication has not completed to the server that the DS/IS consistency adjuster was run on or when a replication connector to another site has been removed.

If you have multiple sites, you must consider the effect of running DS/IS on system folders. The OAB Version 2 folder (a sub folder of offline address book) may cause problems after you run DS/IS. The distinguished name for OAB Version 2 is the same for every site. Therefore, if these folders are accidentally rehomed after you run DS/IS, it may be hard to distinguish which folder originally belonged to which site.

One way to avoid this problem is to change the display name for each OAB Version 2 folder to match the original site before you run the DS/IS switch. To change the display name for the OAB Version 2 site folder:

1. Start the Microsoft Exchange Server Administrator program.
2. Click Folders, expand the system folder Hierarchy, expand the offline address book (under System Folders), and then locate the OAB Version 2 folder.
3. Open the properties of the OAB Version 2 folder, click the General Tab, and then add the site name to the Folder Name box (for example, OAB Version 2 (SiteName)).
4. Click OK.
5. Repeat steps 1-4 for each OAB Version 2 Folder in each site.

After the rehoming process is complete, if you re-create a replication connector to the organization, there is a conflict for each rehomed public folder. The new server wins the conflict because it has the latest changes to the public folders in question. Accordingly, the public folder is homed on the new server, and the new ACL is kept. This results in lost permissions for any users not on the site where the DS/IS consistency adjuster was run.

The DS/IS consistency adjuster is modified in Exchange Server 5.5 and each of these functions (making new directory entries for mailboxes, modifying ACLs in mailboxes, rehoming public folders, and modifying ACLs in public folders) must be selected manually to take effect. Additionally, a new attribute of public folders in Exchange Server 5.5 is to "Limit Administrative Access" to a public folder to a home site, which prevents other sites from being able to rehome those particular folders. Note that this property is only fail-safe in an environment that is completely Exchange Server 5.5. In a mixed version 4.0, 5.0, and 5.5 Exchange Server environment, version 4.0 and 5.0 Administrator Consistency Adjustment programs ignore the Administrative Access flag and rehome the folders anyway.

NOTE: You do not need to run the DS/IS consistency adjuster if you only want to restore an information store to a production server that has a good working directory.

To run DS/IS consistency adjuster:

1. In the Exchange Server 5.5 Administrator program, click a server running Exchange Server 5.5 that contains a public information store.
2. On the File menu, click Properties, and then click the Advanced tab.
3. Click Consistency Adjustment.
4. In DS/IS Consistency Adjustment, select the Remove unknown user accounts from public folder permissions check box, and then select All inconsistencies.

NOTE: Clear all other check boxes.