One of my colleague performed speedy installation of NRPE module in a machine but found that the Nagios server is not able to query that machine.
In Nagios screen it shows:
NRPE: Unable to read output.
Checking from the machine itself, NRPE is giving correct version but throwing same error for any other checks:
$[root@domU:/usr/local/nagios/libexec] ./check_nrpe -H localhost NRPE v2.8 $[root@domU:/usr/local/nagios/libexec] ./check_nrpe -H localhost -c check_load NRPE: Unable to read output
After further digging, I’ve found he installed Nagios-plugins using yum which placed plugins files in some different location then desired by NRPE.
Then I installed nagios-plugins manually:
$ cd /usr/src $ wget http://osdn.dl.sourceforge.net/sourceforge/nagiosplug/nagios-plugins-1.4.6.tar.gz $ tar xzf nagios-plugins-1.4.6.tar.gz $ cd nagios-plugins-1.4.6 $ ./configure --without-mysql $ make $ make install
The problem is resolved immediately.