DFS Replication constant problem


  • DFS Replication is causing me constant problems... is this a reliable way of mirroring data from one server to another?  it doesn't seem so.

    Here's my setup:

    2 Windows 2008 R2 Servers (both Domain controllers) - ServerA and ServerB
    Servers are connected via site-to-site VPN (30mbps+ connection)
    6 Replication Groups each containing 2 replication folders
    ServerB is configured as read-only
    Replication schedule is 24x7, full bandwidth.

    After initial sync, the replication appears to work for a day or so, but then stops. 

    Health Report will issue a Warning:

    This member is waiting for initial replication for replicated folder Folder1.

    Based on other posts, I have learned that using the following command, I can begin replication again however it only works on the root of the folder:

    dfsradmin Membership Set /RGName:RG1 /RFName:RF1 /MemName:ServerA /IsPrimary:True

    Sub directories no longer replicate.

    I can fix this by deleting the RF definition, waiting for the AD to replicate,  deleting the "DfsrPrivate" folder on both servers and reconfigure the RF.  It seems to work for a few days.. but then the cycle starts over.

    Tuesday, December 04, 2012 5:51 PM

All replies

  • Hi,

    Re-set Primary server is not a solution unless initial replication is actually not finished. Thus please first check if initial replication is finished:

    When Initial Replication is done, you will receive a 4104 event Downstream. Upstream will never write any events about initial replication due to the PULL nature of DFSR - he has no idea if the downstreams are done.  Also please check if we have a 4112 event Upstream and a 4102 event Downstream.

    If IR is actually finished, please also checked the following registry permissions:

    HKLM\Software\Microsoft\Windows NT\CurrentVersion\Perflib
    Permissions should be:
    Administrators - Full Control
    Creator Owner - Special
    Local Service - Read
    Network Service - Read
    Performance Log Users - Read
    Performance Monitor Users - Read
    System - Full Control


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    Thursday, December 06, 2012 8:52 AM
  • Thanks for responding..

    I do have 4014 events downstream for each RF and the problem reappeared on Friday.

    I checked the permissions for the registry key on both servers (you didn't specify which):

    Perflib key is correct, but with some add'l permissions.

    winreg key was incorrect.  Permissions were: 
    Local Service - Read 
    Administrators - Full Control
    Backup Operators - Special

    I added the permissions you listed but did not remove the add'l permissions.

    Exactly the same as Upstream and I made the same changes.

    I do have a 4112 Upstream for each folder.

    At 9pm on 12/6 two 2107 events were recorded on my upstream server - one for each drive containing RFs - followed by two 2108 events.  Immediately after the 2108 events, my upstream server recorded 4102 events for each RF.  

    I reran the "dfsrdiag /setprimary" commands and now am in the state where the is no "backlog" but the subfolders will not replicate.  I did this before reading your post.

    After having read your post and updated the registry permissions to match your post, I'll "fix" the RF folders and see if this resolves it.
    Sunday, December 09, 2012 4:54 PM
  • As it has been a while since your last reply, please let us know if there is any progress.

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    Tuesday, December 11, 2012 1:19 AM
  • sorry for the delay, it takes about 40 hours for DFS to sync.

    As of now, I have 8 RF folders that are replicating as expected.  If the pattern holds, the replication will continue to work for 2-3 days, then break.  Hopefully the registry permissions changes are the answer.

    Tuesday, December 11, 2012 8:52 PM
  • Here we go again.

    I received 13 4102 events on the upstream server and  7 4102 events on the downstream server for my 8 RFs.  They started happening within minutes of the scheduled start time of my Image backup.

    None of the 8 RFs are replicating (I tested by creating an empty text file in each directory).

    Monday, December 17, 2012 2:40 PM
  • I can now replicate the problem fairly quickly. 

    2 Windows Server 2008 R2 boxes
    1 Replicated Folder with one server marked as "Read-Only"

    I wait for them to sync (I receive a 4104 on the downstream server).

    I then start a Windows Server Backup:

    Backup Once, Full Server, backed up to a USB drive that is not involved in DFS.  Within 3 minutes of starting the backup, I receive a 4102 error on the upstream server indicating that DFS is broken.

    This pattern persists even if the DFS Replication service is stopped when the backup is run.  As soon as the service is restarted, the error appears.

    Any other ideas?

    Wednesday, December 19, 2012 3:56 PM
  • Anyone out there from MS with an idea or a fix to let me use DFS and the Windows Server Backup?
    Tuesday, January 01, 2013 6:04 PM
  • What are the settings you are using for your backup?  Is it a VSS full or a copy backup?
    Tuesday, January 01, 2013 7:43 PM
  • VSS Full.

    Tuesday, January 01, 2013 7:54 PM
  • Try a copy only backup of the folder in question and see if you get the same issue.  I have had success with this configuration in the past with several implementations.

    Wednesday, January 02, 2013 12:02 AM
  • Sorry for the delay.  I didn't mark any of these as answers or helpful because they all focused on the backup.  My problem is with the DFS configuration.

    Since these posts, I have continued to use DFS but am approaching the end of my rope.  DFS also seems to break when updates are installed and the machine reboots.  Because it is a production server - and we are a small company that cannot afford a lab to test this scenario - I have a very difficult time troubleshooting this.

    Does anyone have any configuration experience with DFS (not backup)?

    Monday, February 18, 2013 2:55 PM