random unmounts on the NFS client - NFS

This is a discussion on random unmounts on the NFS client - NFS ; Hello: Hello, I am running NFS Server, Solaris and NFS client on AIX. I am currently doing hard mounts and not using autofs or automounter. >From time to time, the client loses NFS connectivity with NFS server. I keep getting ...

+ Reply to Thread
Results 1 to 4 of 4

Thread: random unmounts on the NFS client

  1. random unmounts on the NFS client

    Hello:

    Hello, I am running NFS Server, Solaris and NFS client on AIX. I am
    currently doing hard mounts and not using autofs or automounter.

    >From time to time, the client loses NFS connectivity with NFS server.

    I keep getting a RPC timeout issue. I am not sure why this happens.
    The only solution is, force unmount on the client, and restart NFS on
    the server, and everything is working again.

    Any thoughts? Ideas?
    TIA


  2. Re: random unmounts on the NFS client

    On Thu, 12 Jul 2007, Eman On wrote:

    > Hello, I am running NFS Server, Solaris and NFS client on AIX. I am
    > currently doing hard mounts and not using autofs or automounter.
    >
    >> From time to time, the client loses NFS connectivity with NFS server.

    > I keep getting a RPC timeout issue. I am not sure why this happens.
    > The only solution is, force unmount on the client, and restart NFS on
    > the server, and everything is working again.
    >
    > Any thoughts? Ideas?


    Learn to provide proper bug reports.

    Not a lot of information here -- what type of network (switched?), are you
    seeing other network problems, are the failures random or reproducible,
    etc. Versions would be useful.

    Where I work we have SGI clients mounting Solaris exports of a
    hierarchical storage system using switched ethernet. There have been bugs
    in SGI's NFS implementation for files that were staged to tape
    (reproducible with difficulty, since trying to access a staged file
    migrates it back to disk), duplex mismatch problems between the SGI
    machines and the switches, and problems from the switches dropping
    UDP traffic when busy.

    If you are using duplex negotiation, you might consider reconfiguring
    for a fixed setting.

    If you are using UDP on switched ethernet you should try TCP. There are
    some web pages with information on NFS over switched ethernet.

    --
    George N. White III


  3. Re: random unmounts on the NFS client

    On Jul 14, 8:33 am, "George N. White III"
    wrote:
    > On Thu, 12 Jul 2007, Eman On wrote:
    > > Hello, I am running NFS Server, Solaris and NFS client on AIX. I am
    > > currently doing hard mounts and not using autofs or automounter.

    >
    > >> From time to time, the client loses NFS connectivity with NFS server.

    > > I keep getting a RPC timeout issue. I am not sure why this happens.
    > > The only solution is, force unmount on the client, and restart NFS on
    > > the server, and everything is working again.

    >
    > > Any thoughts? Ideas?

    >
    > Learn to provide proper bug reports.
    >
    > Not a lot of information here -- what type of network (switched?), are you
    > seeing other network problems, are the failures random or reproducible,
    > etc. Versions would be useful.
    >
    > Where I work we have SGI clients mounting Solaris exports of a
    > hierarchical storage system using switched ethernet. There have been bugs
    > in SGI's NFS implementation for files that were staged to tape
    > (reproducible with difficulty, since trying to access a staged file
    > migrates it back to disk), duplex mismatch problems between the SGI
    > machines and the switches, and problems from the switches dropping
    > UDP traffic when busy.
    >
    > If you are using duplex negotiation, you might consider reconfiguring
    > for a fixed setting.
    >
    > If you are using UDP on switched ethernet you should try TCP. There are
    > some web pages with information on NFS over switched ethernet.
    >
    > --
    > George N. White III


    Yes, this is a switched 10/100 network. Both the client and server are
    on the same subnet. I am not seeing any network problems, and this
    problem is totally random (as far as I know). We can't seem to
    reproduce the problem, so I say its random. We are using NFS version
    3 with tcp, according to nfsstat -m

    The media duplex speed between server and client are set to 10/100
    Full Duplex (no auto negotiate).

    We haven't had the problem yet. But once it occurs, I am not really
    sure how to troubleshoot or find the "root cause". I will try to do a
    tcpdump on the client to see whats going. As I was saying, on the
    client side: the mounts go bad and RPC timeout error.






  4. Re: random unmounts on the NFS client

    On Sun, 15 Jul 2007, Eman On wrote:

    > On Jul 14, 8:33 am, "George N. White III"
    > wrote:
    >> On Thu, 12 Jul 2007, Eman On wrote:
    >>> Hello, I am running NFS Server, Solaris and NFS client on AIX. I am
    >>> currently doing hard mounts and not using autofs or automounter.

    >>
    >>>> From time to time, the client loses NFS connectivity with NFS server.
    >>> I keep getting a RPC timeout issue. I am not sure why this happens.
    >>> The only solution is, force unmount on the client, and restart NFS on
    >>> the server, and everything is working again.

    >>
    >>> Any thoughts? Ideas?

    >>
    >> Learn to provide proper bug reports.
    >>
    >> Not a lot of information here -- what type of network (switched?), are you
    >> seeing other network problems, are the failures random or reproducible,
    >> etc. Versions would be useful.
    >>
    >> Where I work we have SGI clients mounting Solaris exports of a
    >> hierarchical storage system using switched ethernet. There have been bugs
    >> in SGI's NFS implementation for files that were staged to tape
    >> (reproducible with difficulty, since trying to access a staged file
    >> migrates it back to disk), duplex mismatch problems between the SGI
    >> machines and the switches, and problems from the switches dropping
    >> UDP traffic when busy.
    >>
    >> If you are using duplex negotiation, you might consider reconfiguring
    >> for a fixed setting.
    >>
    >> If you are using UDP on switched ethernet you should try TCP. There are
    >> some web pages with information on NFS over switched ethernet.
    >>
    >> --
    >> George N. White III

    >
    > Yes, this is a switched 10/100 network. Both the client and server are
    > on the same subnet. I am not seeing any network problems, and this
    > problem is totally random (as far as I know). We can't seem to
    > reproduce the problem, so I say its random. We are using NFS version
    > 3 with tcp, according to nfsstat -m


    Based on my experiences, you should look carefully at the switch
    (especially if you don't have hierarchical storage or some other
    problem causing latency on the server).

    There are some general documents about NFS and switched ethernets on the
    web. You may be able to make it fall over using a tool to generate heavy
    RPC traffic. Have a look at


    > The media duplex speed between server and client are set to 10/100
    > Full Duplex (no auto negotiate).


    Does 10/100 mean one end is 10 and the other 100? We set the ports on
    the switch to 100-FD, on the SGI workstations we have to build a custom
    kernel to turn off autogegotiation.

    > We haven't had the problem yet. But once it occurs, I am not really
    > sure how to troubleshoot or find the "root cause". I will try to do a
    > tcpdump on the client to see whats going. As I was saying, on the
    > client side: the mounts go bad and RPC timeout error.


    At one time we had problems with the switches cutting off systems that
    didn't fit the vendor's idea of "normal Windows PC client traffic
    patterns". The switch had a setting for "server" ports. Can you peek at
    the logs for the switch?

    --
    George N. White III


+ Reply to Thread