NRPE Check failures



I recently patched one of our RHEl4 boxes and a strange problem hasnow occurred with check_load plugin. Nagios is generating Unable to read output error.

I ssh’d onto the box as root and ran the check_load plugin manually and returned info fine:
[root@dns2 local]# /usr/local/nagios/libexec/check_load -w 15,10,5 -c 30,25,20
OK - load average: 0.00, 0.01, 0.00|load1=0.000;15.000;30.000;0; load5=0.010;10.000;25.000;0; load15=0.000;5.000;20.000;0;

If I do the same and logon as nagios (nrpe user) then I get no output.

I have enabled debug = 1 in the nrpe.cfg file but the only messages I receive are

 Oct 31 13:02:02 dns2 nrpe[7124]: INFO: SSL/TLS initialized. All network traffic will be encrypted.

Any ideas? I am assuming that some dependency on some external lib’s somewhere but I dont know how to debug any deeper than this.



Hi, have you tried using "strace "?

It should give you a list of all the system calls, including file opening requests. Try running it as root and as nagios user and make a difference.

Good luck


Thanks Aivan! :smiley:
Strace did the trick, turns out nagios user had no access to /proc/loadavg which is what the plugin executes.