Disk usage as percentage of used disk

Hi! Maybe someone here can explain this as I am new to Grafana. I would like to see the used disk in percentage when using the piechart. I am using graphite as datasource and Nagios (Check MK) sends it data to Graphite.

No matter what I try with percentage of and so on I still do not get the right pie chart. See the image here for details. The chart should be 50/50 in this case.

You want to graph used and free, not used and size. The percentages are correct, they’re just being calculated as a percentage of the graph total so you want the graph total to be the total size of the disk (not the size plus the used amount).

Hi, have you solved that problem? I have the same challange here:
https://community.grafana.com/t/subtract-two-values-with-graphite-possible/1839/1

i also do not have the free value right now. I think as workaround a math function (subtract “used” from “total”) could help here.