XADM: How to Compare USNs for Intrasite Replication (182963)


The information in this article applies to:

  • Microsoft Exchange Server 4.0
  • Microsoft Exchange Server 5.0
  • Microsoft Exchange Server 5.5
This article was previously published under Q182963

SUMMARY

This article describes the procedure for determining whether an object is being properly replicated, based on the object's update sequence number (USN). This procedure should be used as one of the steps in verifying intrasite directory replication.

MORE INFORMATION

If the USN-Changed numbers are being increased above the USN of the modified or new object, then that directory is capable of verifying changes made to its directory entries. If you are unable to perform an Update Now, then you will be unable to perform the USN procedure.

For further information on intrasites, see the following Microsoft Knowledge Base articles:

166312 Replication or Knowledge Consistency Check Fails

176459 DirRep Bridgehead Errors Modifying Site Naming Contexts

170334 Troubleshooting Intrasite Directory Replication

Procedure

SERVER 1 = Problem server
SERVER 2 = A server in the site that successfully replicates

NOTE: This procedure needs to be performed in the Exchange Server Administrator program in raw mode on any server involved.

WARNING: Using the raw mode of the Exchange Administrator program (admin /r) incorrectly can cause serious problems that may require you to reinstall Microsoft Windows NT Server and/or Microsoft Exchange Server. Microsoft cannot guarantee that problems resulting from the incorrect use of raw mode can be solved. Use raw mode at your own risk.

  • To initialize raw mode, from the command prompt, in the EXCHSRVR\BIN directory, type the following:

    admin /r

  1. From Server 1 and Server 2, select the configuration object and select File / Raw properties.
  2. Write down the numbers for the following items on the two servers:

    USN-Changed
    USN-Source
    Reps-From (for the other server involved in the test. For example, if you are connected to Server 1, select Reps-From, select Server 2, and double-click. When the screen opens, click OK, and then write down the USN.)

  3. Make a change to an object or create a new object while connected to Server 1. Notice the object's USN-Changed by viewing its raw properties. This number should be higher than the configuration object's USN-Changed number.
  4. Go to Configuration / Servers / Server 1 - Directory Service, and perform an Update Now (select Refresh All Items in the Directory).
  5. Verify that the USN-Changed on the configuration object is now higher than the USN-Changed of the new or modified object mentioned in step 3. If not, there's a problem with the directory on Server 1.
  6. Connect to Server 2 and perform an Update Now (Refresh All Items in the Directory). The USN-Changed on Server 2 should match USN-Source on Server 1 (if there have been no other updates performed on Server 1).
  7. The new or modified object should be viewable from Server 2, and the USN- Changed on Server 2 should match the USN-Source on Server 1.
  8. Repeat steps 2-7 while connected to Server 2, replacing each entry of Server 1 with Server 2.
Modification Type:MinorLast Reviewed:4/28/2005
Keywords:kbhowto kbusage KB182963
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