Nagios Support Forum

Hi all.

I get NRPE: Unable to read output for the following services: Cron, ssh, and syslog daemon. I also get 'UNKNOWN: iostat not found or is not executable by the nagios user' for CPU Stats monitoring. Any thoughts on how to fix these?

System being monitored
OS: Ubuntu 10.04
Agent: nagios-agent installed via repos

iostat is in the sysstat package on Red Hat and CentOS systems. Try running the following command to (re)install it: Regarding the NRPE error, can you post your command definitions both on the Nagios side and the NRPE client side?

I added some background info to the original post.

I've tried using apt-get to install iostat but it seems like there isn't such a package available for Ubuntu. Is it a sub-part of another package or do I need to use a completely different utility?

Nagios server side:
CPU: $USER1$/check_nrpe -H $HOSTADDRESS$ -t 30 -c $ARG1$ $ARG2$ (ARG1=check_cpu_stats ARG2=-a '-w 85 -c 95')
Cron: "..." (ARG1=check_init_service ARG2=-a 'crond')
Syslog: "..." (ARG1=check_init_service ARG2=-a 'syslog')

I'm not sure where to find the definitions on the host side since the agent was installed via repo.

cwscribner wrote:I've tried using apt-get to install iostat but it seems like there isn't such a package available for Ubuntu. Is it a sub-part of another package or do I need to use a completely different utility?

iostat should be part of the sysstat package

That did the trick for the CPU monitoring.

Now I just have to get NRPE working...

cwscribner wrote:That did the trick for the CPU monitoring.

Now I just have to get NRPE working...

Lets look in

Here's the nrpe.cfg file on the monitored server.

In this file you will need to set dont_blame_nrpe=1 because you are passing args from your Nagios server.

but this also assumes that nrpe was compiled with and I'm not sure at this moment what the RPM does.

Additionally, the folders /etc/nagios/nrpe.d/ is included and their is likely a commands.cfg file in their

Also in this configuration is
include=/etc/nagios/nrpe_local.cfg

so their may be overriding configurations in that file...

So nrpe_local.cfg contained nothing. I found one file in nrpe.d that had configuration directives in it. I've attached it.

on my ubuntu test machine my cron is named cron instead of crond, ssh is ssh instead of sshd
you should be able to check yours with To make these changes, in XI change the $ARGS1$ from -a 'crond' to -a 'cron'

This was one of the reasons why we had disabled the ubuntu & debian in the wizard.

I'll try to get these sorted for the next release of the wizard.