Configuring for Network Filesystems

<sect1 id="postlfs-config-netfs"  xreflabel="netfs">
<?dbhtml filename="netfs.html" dir="postlfs"?>
<title>Configuring for Network Filesystems</title>

<para>While <acronym>LFS</acronym> is capable of mounting NFS volumes from
the get go, the lfs-bootscripts are not quite ready for this configuration.
Network filesystems should be unmounted before the network goes down.  The
<filename>netfs</filename> script below will prepare your LFS for mounting
network filesystems at boot time, and unmounting them when the network 
is stopped.</para>

<para>  The following commands will create the <filename>netfs</filename>
script:</para>

<screen><command>cat &gt; /etc/rc.d/init.d/netfs &lt;&lt; "EOF"</command>
#!/bin/sh
# Begin $rc_base/init.d/netfs
                                                                                
# Based on sysklogd script from LFS-3.1 and earlier.
# Rewritten by Gerard Beekmans  - gerard@linuxfromscratch.org
# netfs script written by Nathan Coulson - conathan@conet.dyndns.org
# and by DJ Lucas - dj@lucasit.com
                                                                                
. /etc/sysconfig/rc
. $rc_functions
                                                                                
case "$1" in
                                                                                
        start)
                # The following line mounts all entries in fstab that
                # have the _netdev option.  This is required for network
                # filesystems to be mounted at boot time.
                echo "Mounting network volumes..."
                mount -a -O _netdev
                evaluate_retval
                ;;
                                                                                
        stop)
                echo -n "Unmounting network volumes..."
                                                                                
                # The following line obtains a list from the output of
                # mount for all netfs types and anything that was
                # mounted with the _netdev option.
                NETMOUNTS=`mount | grep '_netdev\|smbfs\|ncpfs|\coda\|nfs' \
                        | cut -d " " -f 3 | sed 's/$/ /g'`
                                                                                
                # Check to see if anything was listed from above
                # (see if anything is actually needs to be unmounted)
                if [ x"$NETMOUNTS" != x ]
                then
                        # There is something mounted
                        # terminate the echo -n above
                        echo " "
                                                                                
                        # Try and stop processes the nice way
                        # (probably won't work in most cases)
                        fuser -m -SIGTERM $NETMOUNTS &gt; /dev/null
                                                                                
                        # Check and see if it found anything.  If it
                        # did, then give 3 seconds for things to exit
                        # the nice way before killing them off.  
                        # This one will work all of the time!
                        if [ $? == 0 ]
                        then
                                sleep 3
                                fuser -km $NETMOUNTS &gt; /dev/null
                        fi
                                                                                
                        # We now need to unmount all network filesystems.
			# We will do this with two umount commands to allow
			# for broken behavior of smbmount, and also to make
			# certain that netmounts without the _netdev option
			# will still get unmounted.
                        umount -a -O _netdev
                        # save the retval
			if [ $? != 0 ]
			then
				NERRVAL=1
			fi

			# Now catch the rest of the network filesystems
			# by fstype.  This list can be extended later as
			# more network filesystems are supported by mount.
			umount -a -t coda,ncpfs,nfs,smbfs
			if [ $? == 0]
			then
				[ -z $NERRVAL ]
				evaluate_retval
			else
				# make certain that we return an error
				/bin/false		
				evaluate_retval
			fi
                else
                        # There is nothing mounted
                        echo "No network volumes mounted!"
                        # print a nice '[  OK  ]' message
                        evaluate_retval
                fi
                ;;
                                                                                
*)
                echo "Usage: $0 {start|stop}"
                exit 1
                ;;
esac
                                                                                
# End $rc_base/init.d/netfs
EOF
<command>chmod 0755 /etc/rc.d/init.d/netfs</command></screen>

<para>While the excessive comments in the script might make people cringe, the
important part to note is that network filesystems that should be mounted at
boot time, must have the <emphasis role="strong">_netdev</emphasis>
option passed to them in <filename>/etc/fstab</filename>.</para>

<para>Now put the necessary symlinks in place.</para>

<screen><command>ln -sf ../init.d/netfs /etc/rc.d/rc0.d/K47netfs &amp;&amp;
ln -sf ../init.d/netfs /etc/rc.d/rc1.d/K47netfs &amp;&amp;
ln -sf ../init.d/netfs /etc/rc.d/rc2.d/K47netfs &amp;&amp;
ln -sf ../init.d/netfs /etc/rc.d/rc3.d/S28netfs &amp;&amp;
ln -sf ../init.d/netfs /etc/rc.d/rc4.d/S28netfs &amp;&amp;
ln -sf ../init.d/netfs /etc/rc.d/rc5.d/S28netfs &amp;&amp;
ln -sf ../init.d/netfs /etc/rc.d/rc6.d/K47netfs</command></screen>

</sect1>