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RPC Server Unavailable when trying to Show Root in DFS

    Question

  • Recently we have been unable to view the root in DFS.  We are running Windows 2003 (standard) with SP 2.  We can not view it from the servers themselves (file servers or DC) or from our Windows XP SP3 PCs.  
    We keep our servers and workstations patched and it seems to have stopped working about a month ago or so.  We don't get into it very often since it basically runs itself, so I am really unsure exactly when it stopped working.

    The only error we get is 'RPC Server is Unavailable'.  There are not any event logs generated including in the File Replication Service logs in Event Viewer.  

    It does seem that everything is still replicating fine, but we need to use it for another job and we can no longer access it.

    I've been searching for a resolution for several days now and there are plenty of articles relating to RPC Server problems, but none that address this situation.

    NOTE:  I have verified RPC Server IS running on all the servers in question.

    Any help or insight would be greatly appreciated!

    Thanks! 
    Wednesday, September 3, 2008 3:13 PM

Answers

  • Please make sure that "Distributed File System" is running on all the root targets and all of your DCs. I can't see from your initial message whether you specifically looked for the DFS service or on which machines you checked.

    The next thing to check is whether, for the problem namespace(s), one of the root targets is downed or was otherwise decommisioned without removing it from the namespace. If you access the root:

        dir \\domain\namespace

    this should prime the DFS cache to guarantee that the management console will find a live target to do management operations on. It is possible there is a problem in failing over from a downed target in the management path.

    If there is such a root target, the management console will let you remove it (perhaps with a warning that the server is unavailable, but it will allow it to be forced out).
    • Marked as answer by David Shen Monday, September 8, 2008 2:14 AM
    Friday, September 5, 2008 11:04 PM

All replies

  • Hi Sarlin,

     

    Can you see any error event in the DFS application within Event Viewer? If there is any error, please describe them here to narrow down the issue.

     

    Did you encounter "RPC Server is Unavailable" error message while you attempt to display the DFS root details within the DFS snap-in?

     

    Troubleshoot steps:

     

    1. Please launch nslookup on both the problematic server and client to check if you can resolve the name of the DFS server into IP address successfully.

     

    2. Please check if you can access the DFS member servers respectively via \\ipaddressofDFSserver

     

    3. Please also verify that all the domain based DFS root servers are online.

     

    4. The DFS client caches a portion of the PKT that is known as the referral. Therefore, if the DFS client has connected to a DFS root target or to a DFS link target, the DSF client favors connecting to that server again until the cache expires. Please run the following command on the problematic servers and clients and then check if you can access the DFS root again.

     

    Dfsutil /pktflush

     

    Dfsutil /spcflush

     

    5. Please verify that "Distributed File System" service is to Automatic started and attempt to recreate the root again.

     

    6. Please confirm that the following registry values are present and valid on the DFS member server.

     

    Key: HKLM\Software\Microsoft\DFSHost\Volumes

     

    Value: FTDfs

    Type: REG_SZ

    Data: <name of root>

     

    Value: RootShare

    Type: REG_SZ

    Data: <name of root>

     

    Note: The following value will only be present for a Domain DFS root

     

    Value: FTDfsObjectDN

    Type: REG_SZ

    Data: <DN for DFSroot object in AD>

    Example:

    CN=MyDFSroot,CN=Dfs-Configuration,CN=System,DC=MyDomain,DC=com.

     

    HKLM\SOFTWARE\Microsoft\Dfs\Roots\Domain\DFS

    "RootShare"="DFS"

    "LogicalShare"="DFS"

     

    7. Please follow the steps to check if the issue can be resolved.

     

    a. On the server that will be added as a domain based DFS root target create a share that is the same name as the DFS root

     

    Note: It MUST be the same name as the DFS root otherwise a new root with the share name will be created

     

    b. From a command prompt run the following:

     

    dfsutil /addftroot /root:\\<fqdn of domain>\<dfs root> /server:<servername to be added as dfs root> /share:<dfs root share>

     

    c. A reboot may be required of the PDC and/or the server being added. Try to access the Distributed File System snap-in to see if the DFS root is accessible before any reboots

     

    EX:

     

    DFS root: root.local\dfsroot

    Server to be added: MEMBER1

     

    Once share is created on MEMBER1 called dfsroot run:

     

    dfsutil /addftroot /root:\\root.local\dfsroot /server:member1.root.local /share:dfsroot

     

    Hope it helps.


    David Shen - MSFT
    Thursday, September 4, 2008 11:36 AM
  •  

    Ok, to answer some of your questions:

    I did encounter the "RPC Server is Unavailable" error message while attempting to display the DFS root details in the DFS snapin.

    I can resolve all the servers via nslookup.

    I can access the servers with file://ipaddressofdfsserver/

    All the servers are online.

    I ran both the dfsutil /pktflush and dfs /spcflush on the servers except the target server since it doesn't have the admin tools installed. 

    "Distributed File System" service is set to start automatically on all the servers in question.

    The registry values are not present on the servers that you outlined.  I started to add them, but stopped since the service has been in use for several years and just recently stopped working.  It worked without those values.  Additionally, I was able create a new DFS test root and successfully connect to it several times with no problem and without these registry values.

    I also haven't done the last recommended step.  I guess I'm just wondering if some recent update broke the existing links.  Some of the target folders have a LOT of information in them and if I have to recreate them it will take a considerable amount of time to replicate that information over again. 

    Thursday, September 4, 2008 4:02 PM
  • Please make sure that "Distributed File System" is running on all the root targets and all of your DCs. I can't see from your initial message whether you specifically looked for the DFS service or on which machines you checked.

    The next thing to check is whether, for the problem namespace(s), one of the root targets is downed or was otherwise decommisioned without removing it from the namespace. If you access the root:

        dir \\domain\namespace

    this should prime the DFS cache to guarantee that the management console will find a live target to do management operations on. It is possible there is a problem in failing over from a downed target in the management path.

    If there is such a root target, the management console will let you remove it (perhaps with a warning that the server is unavailable, but it will allow it to be forced out).
    • Marked as answer by David Shen Monday, September 8, 2008 2:14 AM
    Friday, September 5, 2008 11:04 PM