NRPE: Unable to read output

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.

This entry was posted on Thursday, October 16th, 2008 at 4:57 pm and is filed under Monitoring. You can follow any responses to this entry through the RSS 2.0 feed. You can leave a response, or trackback from your own site.

4 Responses to “NRPE: Unable to read output”

Steve on March 16th, 2010 at 12:36 am

Thanks, it solves my problem
Neghost on December 15th, 2010 at 3:24 pm

Thank you for your post. This help me to solve the same problem
vicfromsky on May 2nd, 2011 at 10:26 pm

This work for me:

The check_nrpe plugin returns “NRPE: Unable to read output”
This error indicates that the command that was run by the NRPE daemon did not return any character output.
This could be an indication of the following problems:
– An incorrectly defined command line in the command definition. Verify that the command definition in your
NRPE configuration file is correct.
– The plugin that is specified in the command line is malfunctioning. Run the command line manually to make
sure the plugin returns some kind of text output

command[check_sda5]=/usr/local/nagios/libexec/”check_disk” -w 20% -c 10% -p /dev/sda5 <– "check_disk"
jagbir on May 3rd, 2011 at 8:47 pm

@vicfromsky, Thanks for the comment and valuable information about the check.

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