Very confused with MIBs, custom OIDs and alerts

Hello! I have several Linux systems that i monitor in LibreNMS. I want to add alert that will inform me when inode usage on / filesystem is over 85%.

I have found that UCD-SNMP-MIB supports that, i can run snmpwalk with OID 1.3.6.1.4.1.2021.9.1.10.1 and it returns me a integer value of % of used inodes on /

However i am struggling with understanding how to add this OID as a alert condition. I modified the discovery file that is used for Linux systems, but after running daily.sh i still cannot find any condition that would be named “dsk…”:

Can you help me understanding if the steps i made are correct? Thank you in advance

Hi,

The sensor type you want is “percent”. That must be written :

modules:
    sensors:
        percent:
            data:

That should discover correctly after.

Bye

Hi, thanks, but i still have NO IDEA why this is not working…

I modified the discovery/linux.yaml and rediscovered my device, there is no new graph, no new sensor detected, and no alert condition that from which i could create a alert rule…

Why this is SO COMPLICATED… i literally only want to receive one value and make simplest alert ever

The indentation for data: is wrong in the above capture. Then you can run a ./discovery.php -v -d -m sensors -h <idOfTheDevice>. That should help you find out what’s going on.

When the percent sensor will be discovered, alering will be simpler. The force of LibreNMS is that most of the data is discovered by default. So yes, it is a little bit more complicated to add a value that is not yet supported, but you do it only once …