sudo apt install rrdtool imagemagick
rrdtool create ntp1.rrd
--start now-2h --step 1s
DS:req:GAUGE:5m:0:120000
RRA:AVERAGE:0.5:1s:10d
RRA:AVERAGE:0.5:1m:90d
RRA:AVERAGE:0.5:1h:18M
RRA:AVERAGE:0.5:1d:10y
sudo crontab -e -u www-data */5 * * * * /srv/leontp/ntp_png
./install