Some people wish to have updatedb only include mount points which are
automatically mounted by "mount -a", which mounts devices listed in
/etc/fstab. 

The following lines may be added to /etc/updatedb.conf to exclude
non-automatic mount points from updatedb.  Add before the
"export PRUNEPATHS" line in /etc/updatedb.conf. 

# mount points not to be scanned (regexp matching lines into /etc/fstab)
EXCLUDE_MOINT_POINTS=noauto
EXCLUDE_PATH=`awk "/^#/ {next}; /$EXCLUDE_MOINT_POINTS/ {print \\$2}" < /etc/fstab | tr '\012' ' '`
PRUNEPATHS="$PRUNEPATHS $EXCLUDE_PATH"

This suggestion is due to Eric Delaunay
<delaunay@lix.polytechnique.fr>

