Nagios Support Forum

Hi Team,
We configured Disk alerts on Linux Machine for /, today disk space 100% full but Nagios did not send any email regarding disk alert also not showing on GUI, Please find out the attachment.


Thanks

Have you tested your check from the command line? Does it work fine when you run it in a terminal? It is possible that Nagios XI doesn't show you the expected output in the GUI, and doesn't notify you , because you have exceeded your license limits (as per your screenshot).

We configured Nagios on other Linux machine and the Linux machine total Drive size is 30GB and Nagios showing free space is 41GB, Please find out the attachment for the same. Also, we faced same issue with all Linux machines.

Can you show us the actual command that you are using for this service, run from the command line, along with the output of it?

Also, log into the Nagios Core interface: find the "Check Disk" service and show us a screenshot of the page.

Please find out the attachment

First off, you need to add a "%" sign to your thresholds. If you just use an integer, the check will look into the MB of free space, not percentages.

-w, --warning=INTEGER
Exit with WARNING status if less than INTEGER units of disk are free
-w, --warning=PERCENT%
Exit with WARNING status if less than PERCENT of disk space is free
-c, --critical=INTEGER
Exit with CRITICAL status if less than INTEGER units of disk are free
-c, --critical=PERCENT%

Second, the plugin generates an alert if free space is less than one of the threshold values. So, you would need to probably changes your check from this: to this: This way, if free space is less than 20% (but more than 15%), you would get a "WARNING". If the disk space is less than 15%, you would get a "CRITICAL".

after changing the command
/usr/local/nagios/libexec/check_disk -w 20% -c 15% -p /

still getting the same wrong alerts. Please find out the attachment.

This looks correct, it is returning OK as you have more than 20% free

It look not correct. Total disk size of "/" is 20GB only and output is free space of "/" is 41325MB almost 40GB

Oh I see, that is odd

what version of the plugin are you running?

/usr/local/nagios/libexec/check_disk -h |head -5