[PLUG] Problem nfs-mounting "large files"

[Galen Seitz]

Dean S. Messing <deanm at sharplabs.com> wrote:

> But from my google reading I see that mountd v2 seems to have "the problem" with
> large files, and v3 does not.
> 
> On the server machine:
> 
> rpcinfo -p |fgrep mountd
> 
>     100005    1   udp    846  mountd
>     100005    1   tcp    849  mountd
>     100005    2   udp    846  mountd
>     100005    2   tcp    849  mountd
>     100005    3   udp    846  mountd
>     100005    3   tcp    849  mountd
> 
> Any idea how to control which "mountd" gets used when I nfs-mount from the
> client.

>From the FAQ:

  A4. How can I prevent the use of NFS Version 2, or of other NFS versions?

    A. The protocol version is determined at mount time, and can be
    modified by specifying the version of the NFS protocol, or the
    version of the transport protocol, supported by the server. For
    example, the client mount command

    mount -o vers=3 foo:/ /bar will request that the server use NFS
    Version 3 when granting a mount request (Note that "vers" and
    "nfsvers" have the same meaning in the mount command; The string
    "vers" is compatible with NFS implementations on Solaris and other
    vendors). If you wish to prevent use of NFS Version 2 in all cases,
    then you must restart rpc.mountd on the server, with the option "-N
    1 -N 2". The best way to do this is to modify the nfs rpc.mountd
    configuration on the server by modifying the NFS startup script
    options, and then shutting down and restarting NFS as a whole:

        * cd /etc/rc.d/init.d
        * Modify RPCMOUNTDOPTS in the nfs script to include "-N 1 -N 2"
        * Restart nfs (you must have root access) with "./nfs restart"

    You will now get the following error when attemping to nfs mount a
    file system using NFS Version 2 (now unrecognized) after restarting
    rpc.mountd:

    mount: RPC: Unable to receive; errno = Connection refused

    You will also subsequently get the following (non-fatal) warning
    when you unmount any nfs mounted file system at all, regardless of
    when it was mounted:

    Bad UMNT RPC: RPC: Program/version mismatch; low version = 3, high version = 3



Once you've done the mount, I think you should be able to confirm the
version by watching the stats change in the nfsstats report.

galen