db@desktop:/home/db/work/rrdtool> cat create-graphs.sh 
#!/bin/sh
rrdtool create bandwidth.rrd --start N --step 5 \
  DS:incoming:COUNTER:60:0:U \
  DS:outgoing:COUNTER:60:0:U \
  RRA:AVERAGE:0.5:1:120960 \
  RRA:MAX:0.5:1:120960 \
db@desktop:/home/db/work/rrdtool>