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Server 2008 R2 DFS Drop Outs

    Question

  • I have a problem with a Server 2008R2 running DFS, 3 out of 4 Folders drop out - I just can't figure out what on earth is going on.

    It is a Domain based DFS, the namespace is called 'dfs' - e.g. \\domain\dfs, I have 4 Folders called "MyDocs", "Home", "Shared" and "Software" - all of these have a cache duration of 1800 seconds.

    "MyDocs" is used with My Documents Folder Redirection, Home, Shared and Software are used with Group Policy Preference based drive mappings.

    The problem I have is the Home, Shared and Software Folders simply disappear, thus mapped drives become unavailable. The problem can occur as frequently as every 5 minutes or if I'm lucky, I'll get half an hour of solid reliable DFS usage.

    I half suspect I'm not having a problem with the MyDocs Folder because it's linked to Offline files and Windows 7 Offline Files uses background sync.

    One thing I will point out, the problem only surfaced after I upgraded my Lenovo laptop to Windows 7 Ultimate x64 SP1, it did not exist when I was running Windows 7 Professional x64 (no SP). Another laptop on the network (Sony VAIO - differnet WLAN NIC), it's still running Windows 7 x64 Professional (no SP), uses the same WLAN and it never has a problem.

    I have spent months investigating the potential for this to be a WLAN card (Intel Centrino 6200) and I have noticed other people reporting similar mapped network drive issues on the Lenovo forums (also using these Centrino model WLAN cards).

    The problem occurs almost immediately if I try to transfer a large amount of data over the WLAN, e.g. don't bother trying to copy an ISO as will cause the DFS Folders (Home/Software/Shared) to drop-out almost immediately and the copy borkes out. The problem does not occur if I transfer the same ISO over wired LAN ethernet.

    I can't get past the fact that this problem didn't occur when running Win 7 Pro with no SP1, I'm not 100% inclined to think this is a hardware or WLAN card issue.

    I have screwed around with WLAN drivers, power management settings etc etc etc, jack of that. It's achieved nothing.

    I have installed KB983620 but this has had no effect.

    A few things I have noticed:

    * When the DFS Folders come back online, the Application Experience service on the Windows 7 client has literally just (re)started. As a test, sometimes I'll manually restart it and the Folders will reappear almost immediately after (doesn't work every time).

    * Restarting the TCP/IP NetBIOS Helper Service can help force the Folders to come back online (also doesn't work every time)

    * Repeatedly browsing the still functional MyDocs DFS Folder (which never drops out) can help prompt the other DFS Folders to reappear (also doesn't work every time)

    * I have noticed when the 3 DFS Folders are not available via \\domain.local\dfs\, they will be available via \\domain\dfs and vice versa

    * If I run dfsutil /pktinfo - when the 3 Folders are unavailable, the TTL for Home, Shared, Software is sitting at 0 (MyDocs on the other hand is not, it's still counting down). When things are functioning properly, the TTL is counting down for all of them from 1800, when it reaches 0, it starts from 1800 again.

    Any ideas?

    Ben

    
    
    

    • Edited by 2way Technology Monday, July 09, 2012 11:20 AM tiny fonts, bad paragraph spacing. added spacing
    Monday, July 09, 2012 11:18 AM

Answers

  • Hi Ben,

    As you suspect the network card is the cause, could you connect to domain with wireless instead? This could help you bypass the network card to see if issue still exists.

    Also though you mentioned "screwed around WLAN drivers", have you tried to reinstall the driver/find if there is an update from Lenovo's website?

    And if the issue did not occur before installing SP1 for the Windows 7 Pro. So as a part of test, you could also try to uninstall SP1 temporarily to see if it will back to work without SP1:

    http://windows.microsoft.com/uninstallwindows7sp1

    In addition, since you found similar issue on Lenovo forum, have you tried to contect Lenovo to see if it is a known issue, between DFS/SP1 and the Centrino model network card?


    TechNet Subscriber Support in forum |If you have any feedback on our support, please contact tnmff@microsoft.com.

    Wednesday, July 11, 2012 8:09 AM

All replies

  • Hello Ben,

    From your explanation it seems it is wireless issue? can you look in to the event logs of the machine affected and see what event ID is being reported? Also, possibility might be DNS because you said it works with \\domain\dfs but fails with \\domain.local\dfs?

    Can you check your wireless settings to see what is the max data size that can go through if there are such restrictions


    Isaac Oben MCITP:EA, MCSE,MCC View my MCP Certifications

    Monday, July 09, 2012 4:47 PM
  • Hello Ben,

    From your explanation it seems it is wireless issue? can you look in to the event logs of the machine affected and see what event ID is being reported? Also, possibility might be DNS because you said it works with \\domain\dfs but fails with \\domain.local\dfs?

    Can you check your wireless settings to see what is the max data size that can go through if there are such restrictions


    Isaac Oben MCITP:EA, MCSE,MCC View my MCP Certifications

    Hi Isaac

    Thanks for the reply.

    At first and over the past few weeks I've been thoroughly investigating the possibility this is a Wireless issue. Messing around with drivers (Lenovo, Intel, versions, settings, I've tried it all). But there are some factors I can't ignore that lead me to think maybe this is not specifically a Wireless issue.

    1. The problem only started after I upgraded to Windows 7 Ultimate with Service Pack 1 - the problem never occured with Windows 7 Professional (no SP, both x64)
    2. When I first started troubleshooting I was using \\domain\dfs, but then I realised when I was having the problem I could still access the folders via \\domain.loca\dfs. Now I've realised it's a case of when fqdn is working, non-fqdn might not be and when non-fqdn is working, fqdn might not be and sometimes both are not.
    3. No specific events are being generated. Any suggestions?

    Any idea where I check max data rate?

    Thanks,

    ben

    Tuesday, July 10, 2012 10:52 AM
  • Hello Ben,

    Make sure the machine have all the latest updates and see if that helps. Can you try another machine and see if you experience the same behaviour?


    Isaac Oben MCITP:EA, MCSE,MCC View my MCP Certifications

    Tuesday, July 10, 2012 9:30 PM
  • Hi Ben,

    As you suspect the network card is the cause, could you connect to domain with wireless instead? This could help you bypass the network card to see if issue still exists.

    Also though you mentioned "screwed around WLAN drivers", have you tried to reinstall the driver/find if there is an update from Lenovo's website?

    And if the issue did not occur before installing SP1 for the Windows 7 Pro. So as a part of test, you could also try to uninstall SP1 temporarily to see if it will back to work without SP1:

    http://windows.microsoft.com/uninstallwindows7sp1

    In addition, since you found similar issue on Lenovo forum, have you tried to contect Lenovo to see if it is a known issue, between DFS/SP1 and the Centrino model network card?


    TechNet Subscriber Support in forum |If you have any feedback on our support, please contact tnmff@microsoft.com.

    Wednesday, July 11, 2012 8:09 AM
  • Have you found a solution to this yet? I am having the same issue, with NO wireless involved, only desktops. The issue began the time that Desktop redirection was added in the environment. 

    The DFS root is \\domain.local\FS

    There are 5 targets under this root.  On workstations/users desktops (Windows 7 x64 sp1 all updates current) who have the redirection in place, they lose access to all other targets besides the redirected on.

    If I dir \\domain\FS  (not FQDN) all the targets show up, but if I dir \\domain.local\FS (full FQDN) only the one directory is listed, which is the destination of the desktop redirect.

    The problem will resolve itself after 5-15 minutes, sometimes longer. I try dfsutil /pktflush and /spcflush to resolve it quicker, sometimes it works sometimes not. /pktinfo and /spcinfo show correct targets. DNS lookups work fine.

    I have no WINS in the environment and my file servers are in a different switched vlan from the clients, so I would think the client is resolving the shortname with a DNS suffix. The whole thing doesn't make any sense.

    If anyone has any ideas, let me know. Thanks.

    Tuesday, April 09, 2013 6:07 PM