Win2008 Network Shares: Curious Behaviour?

Discussion in 'Server Networking' started by Bastian, Mar 3, 2010.

  1. Bastian

    Bastian Guest

    Hello,

    I'm facing a very curious behaviour these days. I have the following
    test-environment (all Win2008 Servers!):

    - 'SRV' is hosting a network-share '\\srv\share\SRC'
    - 'ClientA' checking for files in \\srv\share\SRC. If a file has found then
    he will do a convert with an 3rd-Party-Tool to \\srv\share\ClientA.
    Converting means that he writes a new file to the ClientA-Folder
    - 'ClientB' checking for files in \\srv\share\ClientA. If a file has found
    the he will do the same (convert) to \\srv\share\ClientB.

    So what happens now, is that ClientA is workling properly without any
    problems. All files found in SRC-Folder will be converted to ClientA-Folder.
    In the next step (Convert by ClientB) ClientB has problems with finding all
    files in Client-A folder. Around 20-30% of the files will be found by ClientB
    and successfully converted to \\srv\share\ClientB (Note: The Client will be
    informed by the Server which file must be converted).

    Now the curious thing: If I'll open \\srv\share\ClientA-Folder on ClientB in
    explorer while ClientB is converting the files within this folder he will
    find ALL files (100%). I've tested this on two different installations and
    the behaviour is everywhere the same. All files will be written correctly by
    ClientA so the files must be found by ClientB. This happens also with shared
    folders located on local and SAN-Disks. The conversion-tool shouldn't be the
    source of this behaviour, too.

    So, is there any sort of file caching on Win2008-Servers? On Win2003-Server
    all is running correctly. Offline-Files are deactivated on both - Server and
    Clients.

    Perhaps somebody can help me with this.

    Best Regards,

    Bastian
     
    Bastian, Mar 3, 2010
    #1
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  2. Hello Bastian,

    If you have problems accessing shared folders on Windows server 2008 check
    the following article about known network problems:
    http://msmvps.com/blogs/acefekay/ar...transfers-or-cause-connectivity-problems.aspx

    Additional make sure to use only the domain internal DNS servers on the NIC
    of all machines. Sometimes it is also helpful to disable IPv6 on the Windows
    server 2008 machine:
    http://blogs.dirteam.com/blogs/paulbergson/archive/2009/03/19/disabling-ipv6-on-windows-2008.aspx

    Best regards

    Meinolf Weber
     
    Meinolf Weber [MVP-DS], Mar 4, 2010
    #2
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  3. Bastian

    Bastian Guest

    Hello Meinolf,

    at first thank you for the fast reply. I've checked all participating server
    for ipv6 and disabled rss and autotuninglevel, but the problem
    still exists.

    I'm stumped...

    Best Regards

    Bastian
     
    Bastian, Mar 4, 2010
    #3
  4. From what you're stating, at this point, I don't think it's network connectivity, and no, caching wouldn't be an issue, unless you are using Redirection. I would suggest to check the application if you can enable logging or check with Process Explorer to see exactly where it's failing. It could be something simple as AV causing it. If not, I'm not sure how your app is checking the folder. If it is using the NtChangeDirectoryNotification event, and the files are being populated quickly, it could also be a timing problem.

    --
    Ace

    This posting is provided "AS-IS" with no warranties or guarantees and confers no rights.

    Please reply back to the newsgroup or forum for collaboration benefit among responding engineers, and to help others benefit from your resolution.

    Ace Fekay, MVP, MCT, MCITP EA, MCTS Windows 2008 & Exchange 2007, MCSE & MCSA 2003/2000, MCSA Messaging 2003
    Microsoft Certified Trainer
    Microsoft MVP - Directory Services

    If you feel this is an urgent issue and require immediate assistance, please contact Microsoft PSS directly. Please check http://support.microsoft.com for regional support phone numbers.
     
    Ace Fekay [MVP-DS, MCT], Mar 4, 2010
    #4
  5. I'm not sure this is the issue, but, Windows Server 2008 has something
    called 'Branch caching'.
    It could be what you're looking for.

    Check out these links:
    http://www.microsoft.com/windowsserver2008/en/us/branch-Cache.aspx?pf=true
    http://blogs.techrepublic.com.com/networking/?p=1081

    Post some info if you solve this one...
     
    Matija Kapraljevic [Revenger], Mar 5, 2010
    #5
  6. Ace Fekay [MVP-DS, MCT], Mar 7, 2010
    #6
  7. Bastian

    Bastian Guest

    Hello,

    BrancheCache is not installed on the servers. I've done some more tests and
    I think I've located the source of my problems.

    I moved the shares '\\srv\share\SRC|ClientA|ClientB' to a windowsxp-client
    and all is running fine. So there must be a problem with the w2k8 server
    hosting the file shares... I've checked the following:

    - AntiVirus-Software => turned off
    - "Caching" (Offline Settings => Files or programs from the will not be
    available offline
    - Folder Archiving and Indexing => turned off

    There must be sth. about sharing where the behaviour of w2k8 is different to
    w2k3/xp/etc...

    Best Regards

    Bastian
     
    Bastian, Mar 9, 2010
    #7
  8. There could be a number of things causing it. What type of clients are accessing it? Is this server a DC?

    If a DC, you may need to disable SMB signing, but that depends on the type of clients accessing it.

    Also, you may want to look at disabling RSS TCP Chimney feature, and IPv6. Read more on it...

    TCP Chimney and RSS Features May Cause Slow File Transfers or Cause Connectivity Problems
    http://msmvps.com/blogs/acefekay/ar...transfers-or-cause-connectivity-problems.aspx

    Ace
     
    Ace Fekay [MVP-DS, MCT], Mar 9, 2010
    #8
  9. Bastian

    Bastian Guest

    Hello Ace,

    RSS TCP Chimney and IPv6 is disabled on all servers. The server hosting the
    shares is an w2k8 enterprise failovercluster (2 nodes) and is not a domain
    controller.

    Best Regards

    Bastian
     
    Bastian, Mar 10, 2010
    #9
  10. Ok, then I assume 'SRV' is the cluster name published in DNS and WINS? Otherwise, I'm assuming you've correctly configured sharing on the 2008 server, cluster or not, and set the Offline settings as such:
    http://www.techotopia.com/index.php/Configuring_Windows_Server_2008_File_Sharing

    Ace
     
    Ace Fekay [MVP-DS, MCT], Mar 10, 2010
    #10
  11. Bastian

    Bastian Guest

    Hello Ace,

    "SRV" ist the dns-name belonging to the clustergroup which is hosting the
    fileshares. I've tested with the ip-address, too. The shares are configured
    as discribed on your link. Setting up a local share (not in a clustergroup)
    hasn't any effect.

    Regards

    Bastian
     
    Bastian, Mar 11, 2010
    #11
  12. Then I am at a loss to figure out what is going on with your share connectivity, unless it's something in the cluster. Maybe someone else can help, or if it persists and causes problems, a call into PSS should be in order.

    Ace
     
    Ace Fekay [MVP-DS, MCT], Mar 11, 2010
    #12
  13. May be mapping to drive letters work.
    jk
     
    Juergen Kluth, Mar 19, 2010
    #13
  14. Bastian

    Bastian Guest

    Hello,

    I've figured out the cause of this behaviour. Disabling SMB 2.0 on the
    Win2008 fileserver looks like to be the solution. So there must be some
    caching mechanism in SMB 2.0 leading to this behaviour. I'll try to get more
    information about this...

    Best Regards

    Bastian
     
    Bastian, May 12, 2010
    #14
  15. Bastian

    Benoit Paris Guest

    Hi Bastian,

    One of our customers is experiencing frequent crashes using our application (I am with a software development firm).

    Using "procmon", I found that the application crashes when the process is looking for a DLL that is located on a Win2K8 network share, and cannot find it. But the DLL is there. I mean, it is in a read-only folder so it cannot really disappear and reappear...

    This is quite similar to the symptoms you are describing. Or is there a question of synchronisation between the copy operations for ClientA and ClientB?

    Also, how did you disable SMB2?

    Any helps or insights are appreciated.


     
    Benoit Paris, Feb 3, 2011
    #15
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