rrdtool create power2.rrd \
--step '5' \
'DS:power:GAUGE:90:U:U' \
'RRA:AVERAGE:0.5:1:720' \
'RRA:AVERAGE:0.5:6:1440' \
'RRA:AVERAGE:0.5:6:2880' \
'RRA:AVERAGE:0.5:12:10080'