Upgrading NFS server

This document describes how to upgrade nfs-utils without trashing NFS. It assumes you have a working NFS already. Check the NFS-HOWTO or linuxsetup23.html for more details on setting up NFS.

If you ever get the urge to upgrade the NFS or rpc commands on your server, think twice. The upgrade may go smoothly or you may lose hours of time struggling to repair the system.

Upgrading

Download new nfs-utils, and grab a copy of portmap (which hasn't changed in quite a while).
nfs-utils = http://sourceforge.net/projects/nfs
portmap = ftp.porcupine.org/pub/security
Backup the following files, which should be in /usr/sbin. If installation fails, copying these files back and reboot should restore the original state.
exportfs
rpc.mountd
rpc.nfsd
rpc.statd
nfsstat
rpc.rquotad
showmount
nhfsstone
nhfsrun
nhfsnums
nhfsgraph
rpc.lockd

Build nfs-utils

     tar -xzvf nfs-utils-1.0.1.tar.gz
     cd *
     configure
     make 
     make install  (as root)

Restart nfsserver

     /etc/rc.d/portmap restart
     /etc/rc.d/nfs restart
     /etc/rc.d/nfsserver restart

If the startup scripts are not present, start NFS server by hand by starting the daemons in the following order:

     portmap
     rpc.mountd
     rpc.nfsd
     rpc.statd
     rpc.lockd
     rpc.quotad (optional)

Test the new server by unmounting and remounting something on a client. On the client, typing 'mount' should print a line like:
dalek:/temporary on /temporary type nfs (rw,addr=192.168.100.2)

Checklist - if it won't start

NFS is difficult to debug because it often writes nothing to any log file. It may not even be obvious whether it is running or not.

Make sure /etc/exports exists and is readable:

   ls -l /etc/exports
   -rw-r--r--    1 root     root          177 Aug  7  2001 /etc/exports
   cat /etc/exports
   /home/shared_stuff    *.my_hostname.com(rw)

Make sure the executables are running on server:

    ps -aux | grep rpc
    root       793  0.0  0.6  1768  824 ? S 17:06 0:00 /usr/sbin/rpc.mountd
    root       798  0.0  0.6  1772  804 ? S 17:06 0:00 /usr/sbin/rpc.nfsd
    ps -aux | grep nfs
    root       798  0.0  0.6  1772  804 ? S 17:06 0:00 /usr/sbin/rpc.nfsd
    ps -aux | grep portmap
    bin        389  0.0  0.4  1340  540 ? S 17:06 0:00 /sbin/portmap

Check the rpc diagnostic tools on server for clues

    /usr/sbin/rpcinfo -p localhost
    program vers proto   port
    100000    2   tcp    111  portmapper
    100000    2   udp    111  portmapper
    100005    1   udp    969  mountd
    100005    2   udp    969  mountd
    100005    1   tcp    972  mountd
    100005    2   tcp    972  mountd
    100003    2   udp   2049  nfs
    100003    2   tcp   2049  nfs

    /usr/sbin/showmount
    Hosts on my_samba_server:
    host1.my_hostname.com
    host2.my_hostname.com

    /usr/sbin/nfsstat
   Warning: /proc/net/rpc/nfsd: No such file or directory
   Server rpc stats:
   calls      badcalls   badauth    badclnt    xdrcall
   0          0          0          0          0       
   Server nfs v2:
   null       getattr    setattr    root       lookup     readlink   
   0       0% 0       0% 0       0% 0       0% 0       0% 0       0% 
   read       wrcache    write      create     remove     rename     
   0       0% 0       0% 0       0% 0       0% 0       0% 0       0% 
   [etc]
   Client rpc stats:
   [etc]
   Client nfs v3:
   [etc]

Try rebooting. Sometimes the NFS server will only start at boot-up.

Make sure NFS server is activated in kernel. This may require compiling a new kernel. The following need to be activated in /usr/src/linux/.config:

   # CONFIG_CODA_FS is not set
   # CONFIG_INTERMEZZO_FS is not set
   CONFIG_NFS_FS=y
   CONFIG_NFS_V3=y
   CONFIG_NFSD=y
   CONFIG_NFSD_V3=y
   CONFIG_SUNRPC=y
   CONFIG_LOCKD=y
   CONFIG_LOCKD_V4=y

(This is for kernel 2.5.5).

As a last resort, if the daemon starts up, get its pid using 'ps' and try strace to find out what it's doing:
# strace -f -p < pid> 2>&1 | tee /tmp/junk

Error messages

nfssvc: Function not implemented
This usually means when you configured the kernel, you didn't modularize or compile in support for "NFS server support". Older kernels may require enabling "experimental" before you can do this.

If the server gets a message like:
carbon portmap[7989]: connect from 192.168.100.2 to dump(): request from unauthorized host
add the client's IP number to /etc/hosts.allow and /etc/exports.
In hosts.allow:
ALL : 192.168.100.2
In exports:
/home/tjnelson 192.168.100.2(rw)
If it says:
Cannot MOUNTPROG RPC: RPC: Program not registered
this means the NFS server is not running.

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