Check active NFS connections - Networking

This is a discussion on Check active NFS connections - Networking ; Is it possible to view active NFS/RPC connections to a server? It's a simple task on the client to just cat mtab. At least, that the *easiest* way. I'd like to be able to look on the server though and ...

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Thread: Check active NFS connections

  1. Check active NFS connections

    Is it possible to view active NFS/RPC connections to a server? It's a
    simple task on the client to just cat mtab. At least, that the
    *easiest* way. I'd like to be able to look on the server though and
    determine if not which clients are connected at least how many there
    are.

    Thanks
    Mathew


  2. Re: Check active NFS connections

    thechillien@gmail.com wrote:
    > Is it possible to view active NFS/RPC connections to a server? It's a
    > simple task on the client to just cat mtab. At least, that the
    > *easiest* way. I'd like to be able to look on the server though and
    > determine if not which clients are connected at least how many there
    > are.


    showmount -a (on the server)
    Chris

  3. Re: Check active NFS connections

    Chris Davies wrote:

    >> Is it possible to view active NFS/RPC connections to a server? It's a
    >> simple task on the client to just cat mtab. At least, that the
    >> *easiest* way. I'd like to be able to look on the server though and
    >> determine if not which clients are connected at least how many there
    >> are.

    >
    > showmount -a (on the server)


    I hadn't heard of this command.
    When I run it I seem to get every computer connected to my server
    by WiFi or ethernet, as seen below.
    What exactly do the 255.255.255.0 directory entries mean?

    --------------------------------
    [tim@alfred ~]$ showmount -a
    All mount points on alfred.murphy.ie:
    192.168.2.0/255.255.255.0:/common
    192.168.2.11:192.168.2.0/255.255.255.0
    192.168.2.14:192.168.2.0/255.255.255.0
    192.168.2.234:192.168.2.0/255.255.255.0
    192.168.2.235:192.168.2.0/255.255.255.0
    192.168.2.4:192.168.2.0/255.255.255.0
    192.168.2.6:192.168.2.0/255.255.255.0
    192.168.2.7:192.168.2.0/255.255.255.0
    192.168.3.0/255.255.255.0:/common
    192.168.3.11:192.168.3.0/255.255.255.0
    192.168.3.2:192.168.3.0/255.255.255.0
    192.168.3.6:192.168.3.0/255.255.255.0
    --------------------------------

    --
    Timothy Murphy
    e-mail (<80k only): tim /at/ birdsnest.maths.tcd.ie
    tel: +353-86-2336090, +353-1-2842366
    s-mail: School of Mathematics, Trinity College, Dublin 2, Ireland

  4. Re: Check active NFS connections

    Timothy Murphy wrote:
    > Chris Davies wrote:
    >
    >>> Is it possible to view active NFS/RPC connections to a server? It's a
    >>> simple task on the client to just cat mtab. At least, that the
    >>> *easiest* way. I'd like to be able to look on the server though and
    >>> determine if not which clients are connected at least how many there
    >>> are.

    >> showmount -a (on the server)

    >
    > I hadn't heard of this command.
    > When I run it I seem to get every computer connected to my server
    > by WiFi or ethernet, as seen below.
    > What exactly do the 255.255.255.0 directory entries mean?
    >
    > --------------------------------
    > [tim@alfred ~]$ showmount -a
    > All mount points on alfred.murphy.ie:
    > 192.168.2.0/255.255.255.0:/common
    > 192.168.2.11:192.168.2.0/255.255.255.0
    > 192.168.2.14:192.168.2.0/255.255.255.0
    > 192.168.2.234:192.168.2.0/255.255.255.0
    > 192.168.2.235:192.168.2.0/255.255.255.0
    > 192.168.2.4:192.168.2.0/255.255.255.0
    > 192.168.2.6:192.168.2.0/255.255.255.0
    > 192.168.2.7:192.168.2.0/255.255.255.0
    > 192.168.3.0/255.255.255.0:/common
    > 192.168.3.11:192.168.3.0/255.255.255.0
    > 192.168.3.2:192.168.3.0/255.255.255.0
    > 192.168.3.6:192.168.3.0/255.255.255.0
    > --------------------------------
    >


    Unfortunately showmount shows everything that EVER mounted, not what's
    currently mounted. Fairly useless if you ask me. I don't know of any
    better alternatives

  5. Re: Check active NFS connections

    Joe Beanfish wrote:

    >
    > Unfortunately showmount shows everything that EVER mounted, not what's
    > currently mounted. Fairly useless if you ask me. I don't know of any
    > better alternatives


    I was about to chip in earlier with "NFS is a stateless protocol" so it's
    hard.

    However, if the OP runs NFS over TCP, rather than UDP, the he could look for
    stuff like the following with "netstat -apl | grep nfs" :


    tcp 0 0 mothra.dionic.net:nfs genghis.dionic.net:792 ESTABLISHED-

    Probably about as good as it gets.


    Cheers

    Tim

    PS - sorry for replying to you, my newsreader lost its cache so I don't have
    the earlier article...

  6. Re: Check active NFS connections

    > Is it possible to view active NFS/RPC connections to a server?

    Chris Davies wrote:
    > showmount -a (on the server)


    Timothy Murphy wrote:
    > When I run it I seem to get every computer connected to my server


    None of these systems ever unmounted the directory. Since NFS is a
    stateless protocol (well, mostly) it's impossible for the server to
    distinguish between a client that's just not using the mount and one
    that's gone away and forgotten about it.

    Chris

  7. Re: Check active NFS connections

    Chris Davies wrote:

    >> Is it possible to view active NFS/RPC connections to a server?

    >
    > Chris Davies wrote:
    >> showmount -a (on the server)

    >
    > Timothy Murphy wrote:
    >> When I run it I seem to get every computer connected to my server

    >
    > None of these systems ever unmounted the directory. Since NFS is a
    > stateless protocol (well, mostly) it's impossible for the server to
    > distinguish between a client that's just not using the mount and one
    > that's gone away and forgotten about it.


    I still don't understand the output of "showmount -a" (below).

    I just rebooted the NFS server (alfred).
    Most of the computers listed are not switched on,
    or are not running Linux,
    and have never mounted a directory on the server.

    As far as I can see, if one computer on a LAN
    has a directory on the server mounted
    then all other computers which are on the LAN,
    or have been on the LAN in the last n weeks,
    are listed.

    Is this normal?
    It is quite possible that my NFS setup is faulty in some way,
    though as far as I know it is completely standard.

    ------------------------
    [tim@elizabeth ~]$ sudo showmount -a alfred
    All mount points on alfred:
    192.168.2.0/255.255.255.0:/common
    192.168.2.11:192.168.2.0/255.255.255.0
    192.168.2.14:192.168.2.0/255.255.255.0
    192.168.2.234:192.168.2.0/255.255.255.0
    192.168.2.235:192.168.2.0/255.255.255.0
    192.168.2.4:192.168.2.0/255.255.255.0
    192.168.2.6:192.168.2.0/255.255.255.0
    192.168.2.7:192.168.2.0/255.255.255.0
    192.168.3.0/255.255.255.0:/common
    192.168.3.11:192.168.3.0/255.255.255.0
    192.168.3.2:192.168.3.0/255.255.255.0
    192.168.3.6:192.168.3.0/255.255.255.0
    ------------------------

    --
    Timothy Murphy
    e-mail (<80k only): tim /at/ birdsnest.maths.tcd.ie
    tel: +353-86-2336090, +353-1-2842366
    s-mail: School of Mathematics, Trinity College, Dublin 2, Ireland

  8. Re: Check active NFS connections

    Timothy Murphy wrote:
    > Chris Davies wrote:
    >
    >>> Is it possible to view active NFS/RPC connections to a server?

    >> Chris Davies wrote:
    >>> showmount -a (on the server)

    >> Timothy Murphy wrote:
    >>> When I run it I seem to get every computer connected to my server

    >> None of these systems ever unmounted the directory. Since NFS is a
    >> stateless protocol (well, mostly) it's impossible for the server to
    >> distinguish between a client that's just not using the mount and one
    >> that's gone away and forgotten about it.

    >
    > I still don't understand the output of "showmount -a" (below).


    showmount -a is not useful. Forget it exists.

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