I think I got this script from a post somewhere on this forum. You might want to do a search if you need more information about it.

#!/bin/sh
#
if ! [ "$USER" = 'root' ]
then
echo "You must be root to run this script!!"
exit 1
fi
#
echo "Removing symlink to nessus in etc directory"
rm -rf /etc/nessus
#
echo "(Re)creating nessus directories under ramdisk"
rm -rf /ramdisk/nessus
mkdir /ramdisk/nessus
mkdir /ramdisk/nessus/plugins
#
echo "creating symlink back to /etc/nessus"
ln -s /ramdisk/nessus /etc/nessus
#
echo "Moving all nessus files from CD to ramdisk"
cp /KNOPPIX/etc/nessus/* /ramdisk/nessus
#
echo "Updating location of plugins in nessusd.conf"
cat /ramdisk/nessus/nessusd.conf | grep -v "plugins_folder" > /ramdisk/scratch
mv -f /ramdisk/scratch /ramdisk/nessus/nessusd.conf
echo "plugins_folder = /ramdisk/nessus/plugins" >> /ramdisk/nessus/nessusd.conf
#
echo "updating plugins"
/usr/sbin/nessus-update-plugins -v