On Raspberry Pi 4B, the temperature sensor data is accessed via `/sys/class/thermal/thermal_zone0/temp` file. It would be nice if OMV can let you specify a command for a generic collectd-rrd graph in the panel. That way temperature can be collected by putting this script in a file in path:
```
head -n 1 /sys/class/thermal/thermal_zone0/temp | xargs -I{} awk "BEGIN {printf \"%.2f\n\", {}/1000}"
```
And use the file name as the command specified.