THOLD - Disk Percentage calculations

[mcutting]

Interesting, as I did not have to do this.

Mind posting your changes ?

[Tommy_dk]

I have patched my Cacti according to the changes in this thread so that I could create thresholds for my Linux-machines, but I just discovered a slight difference in the way the percentage is being calculated.

On Linux the formula is:

Code: Select all

ceil( (<space used> / (<space used>+ <space free>)) * 100)

See: http://en.wikipedia.org/wiki/Df_%28Unix%29

This plugin uses:

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round( (<space used> / <space avail>) * 100, 2)

This example from one of my servers really shows the difference of the outcome:
1. formula: (6446896 / (6446896+778316)) * 100 = 89,22 ~ 90%
2. formula: (6446896 / 7611872) * 100 = 84,58 ~ 84,6%

The difference is quite big on the above example and creates quite a big error margin.

The <space avail> is, as far as i can see, not available in the MIB so that the formula could be changed to use the right values.

Has anyone got any comments on how to fix this?

/Tommy