Unnamed

fs="/ /root /home /var /usr /tmp /opt /etc" 
for f in $fs; do
        name="${f}/_cleanupfile_"
        echo "Creating $name"
        set +e +u
        dd if=/dev/urandom of="${f}/_cleanupfile_"
        sync; sync
        rm "${f}/_cleanupfile_"
        sync; sync
done