Mem usage warning instead of Critical

[benningtonr]

I have a Ubuntu server with 1% mem free, and instead of sending a Critical message, it is just a warning.

WARNING - 140 / 7984 MB (1%) Free Memory, Used: 7844 MB, Shared: 0 MB, Buffers: 1 MB, Cached: 18 MB

check_nrpe!check_mem!-a '-w 20 -c 10'

Ideas, and checking the physical server, it def has only 1% free.

[sreinhardt]

Could you link to which check check_mem plugin you are using please.

[benningtonr]

I am using the out of the box Ubuntu settings that came with Nagios.
Does that make sense, other wise I need to be told where to find that info.

Thanks.

[CGraham]

The "check_mem" command is defined on the Ubuntu server in the nrpe.cfg file.

Run this on the Ubuntu server:

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sudo updatedb

when complete, then run this to find your nrpe.cfg file

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sudo locate nrpe.cfg

Then run this to see your check_mem definition

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sudo cat [location of nrpe.cfg from the previous step] | grep "check_mem"

Finally run this to get the information about the script:

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sudo head [location of the check_mem script in the previous step]

[lmiltchev]

Did you use our linux agent installer? If you did, most probably you are using the "custom_check_mem" plugin, which should be located in "/usr/lib/nagios/plugins/". Try downloading the newer version of this plugin from here:

http://support.nagios.com/wiki/index.ph ... ree_Memory

Override the old one, make it executable (on your client machine!):

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cd /usr/lib/nagios/plugins
chmod +x custom_check_mem
sudo /etc/init.d/nagios-nrpe-server restart

and test it locally:

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./custom_check_mem -w 20 -c 10

From your nagios server, you can test it by running:

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cd /usr/local/nagios/libexec
./check_nrpe -H <client_IP> -c check_mem -a '-w 20 -c 10'

or to factor in the cached memory:

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./check_nrpe -H <client_IP> -c check_mem -a '-w 20 -c 10 -n'

Hope this helps.

[benningtonr]

we are running the requested checks, Buit it seems that this would be a nagios thing, it is seeing less that 10% yet still only shows as a warning.

State: WARNING
Info:
WARNING - 657 / 7810 MB (8%) Free Memory, Used: 7153 MB, Shared: 0 MB, Buffers: 236 MB, Cached: 6365 MB
Date/Time: 2012-12-19 11:55:50

[benningtonr]

Here is the output from the checks:

root@warehouse:/home/helpdesk# updatedb
root@warehouse:/home/helpdesk# locate nrpe.cfg
/etc/nagios/nrpe.cfg
root@warehouse:/home/helpdesk# cat /etc/nagios/nrpe.cfg | grep "check_mem"
root@warehouse:/home/helpdesk# nano /etc/nagioa/nrpe.cfg

It gets to the grep part but returns nothing.

Here are the contents of the nrpe.cfg file:
#############################################################################
# Sample NRPE Config File
# Written by: Ethan Galstad (nagios@nagios.org)
#
# Last Modified: 11-23-2007
#
# NOTES:
# This is a sample configuration file for the NRPE daemon. It needs to be
# located on the remote host that is running the NRPE daemon, not the host
# from which the check_nrpe client is being executed.
#############################################################################


# LOG FACILITY
# The syslog facility that should be used for logging purposes.

log_facility=daemon



# PID FILE
# The name of the file in which the NRPE daemon should write it's process ID
# number. The file is only written if the NRPE daemon is started by the root
# user and is running in standalone mode.

pid_file=/var/run/nagios/nrpe.pid



# PORT NUMBER
# Port number we should wait for connections on.
# NOTE: This must be a non-priviledged port (i.e. > 1024).
# NOTE: This option is ignored if NRPE is running under either inetd or xinetd

server_port=5666



# SERVER ADDRESS
# Address that nrpe should bind to in case there are more than one interface
# and you do not want nrpe to bind on all interfaces.
# NOTE: This option is ignored if NRPE is running under either inetd or xinetd

#server_address=127.0.0.1


# NRPE USER
# This determines the effective user that the NRPE daemon should run as.
# You can either supply a username or a UID.
#
# NOTE: This option is ignored if NRPE is running under either inetd or xinetd

nrpe_user=nagios



# NRPE GROUP
# This determines the effective group that the NRPE daemon should run as.
# You can either supply a group name or a GID.
#
# NOTE: This option is ignored if NRPE is running under either inetd or xinetd

nrpe_group=nagios



# ALLOWED HOST ADDRESSES
# This is an optional comma-delimited list of IP address or hostnames
# that are allowed to talk to the NRPE daemon.
#
# Note: The daemon only does rudimentary checking of the client's IP
# address. I would highly recommend adding entries in your /etc/hosts.allow
# file to allow only the specified host to connect to the port
# you are running this daemon on.
#
# NOTE: This option is ignored if NRPE is running under either inetd or xinetd

allowed_hosts=127.0.0.1



# COMMAND ARGUMENT PROCESSING
# This option determines whether or not the NRPE daemon will allow clients
# to specify arguments to commands that are executed. This option only works
# if the daemon was configured with the --enable-command-args configure script
# option.
#
# *** ENABLING THIS OPTION IS A SECURITY RISK! ***
# Read the SECURITY file for information on some of the security implications
# of enabling this variable.
#

# of enabling this variable.
#
# Values: 0=do not allow arguments, 1=allow command arguments

dont_blame_nrpe=0



# COMMAND PREFIX
# This option allows you to prefix all commands with a user-defined string.
# A space is automatically added between the specified prefix string and the
# command line from the command definition.
#
# *** THIS EXAMPLE MAY POSE A POTENTIAL SECURITY RISK, SO USE WITH CAUTION! ***
# Usage scenario:
# Execute restricted commmands using sudo. For this to work, you need to add
# the nagios user to your /etc/sudoers. An example entry for alllowing
# execution of the plugins from might be:
#
# nagios ALL=(ALL) NOPASSWD: /usr/lib/nagios/plugins/
#
# This lets the nagios user run all commands in that directory (and only them)
# without asking for a password. If you do this, make sure you don't give
# random users write access to that directory or its contents!

# command_prefix=/usr/bin/sudo



# DEBUGGING OPTION
# This option determines whether or not debugging messages are logged to the
# syslog facility.
# Values: 0=debugging off, 1=debugging on

debug=0



# COMMAND TIMEOUT
# This specifies the maximum number of seconds that the NRPE daemon will
# allow plugins to finish executing before killing them off.

command_timeout=60



# CONNECTION TIMEOUT
# This specifies the maximum number of seconds that the NRPE daemon will
# wait for a connection to be established before exiting. This is sometimes
# seen where a network problem stops the SSL being established even though
# all network sessions are connected. This causes the nrpe daemons to
# accumulate, eating system resources. Do not set this too low.

connection_timeout=300



# WEEK RANDOM SEED OPTION
# This directive allows you to use SSL even if your system does not have
# a /dev/random or /dev/urandom (on purpose or because the necessary patches
# were not applied). The random number generator will be seeded from a file
# which is either a file pointed to by the environment valiable $RANDFILE
# or $HOME/.rnd. If neither exists, the pseudo random number generator will
# be initialized and a warning will be issued.
# Values: 0=only seed from /dev/random, 1=also seed from weak randomness

#allow_weak_random_seed=1



# INCLUDE CONFIG FILE
# This directive allows you to include definitions from an external config file.

#include=<somefile.cfg>



# INCLUDE CONFIG DIRECTORY
# This directive allows you to include definitions from config files (with a
# .cfg extension) in one or more directories (with recursion).

#include_dir=<somedirectory>
#include_dir=<someotherdirectory>



# COMMAND DEFINITIONS
# Command definitions that this daemon will run. Definitions
# are in the following format:
#
# command[<command_name>]=<command_line>
#
# When the daemon receives a request to return the results of <command_name>
# it will execute the command specified by the <command_line> argument.
#
# Unlike Nagios, the command line cannot contain macros - it must be
# typed exactly as it should be executed.
#
# Note: Any plugins that are used in the command lines must reside
# on the machine that this daemon is running on! The examples below
# assume that you have plugins installed in a /usr/local/nagios/libexec
# directory. Also note that you will have to modify the definitions below
# to match the argument format the plugins expect. Remember, these are
# examples only!


# The following examples use hardcoded command arguments...

command[check_users]=/usr/lib/nagios/plugins/check_users -w 5 -c 10
command[check_load]=/usr/lib/nagios/plugins/check_load -w 15,10,5 -c 30,25,20
command[check_hda1]=/usr/lib/nagios/plugins/check_disk -w 20% -c 10% -p /dev/hda1
command[check_zombie_procs]=/usr/lib/nagios/plugins/check_procs -w 5 -c 10 -s Z
command[check_total_procs]=/usr/lib/nagios/plugins/check_procs -w 150 -c 200


# The following examples allow user-supplied arguments and can
# only be used if the NRPE daemon was compiled with support for
# command arguments *AND* the dont_blame_nrpe directive in this
# config file is set to '1'. This poses a potential security risk, so
# make sure you read the SECURITY file before doing this.

#command[check_users]=/usr/lib/nagios/plugins/check_users -w $ARG1$ -c $ARG2$
#command[check_load]=/usr/lib/nagios/plugins/check_load -w $ARG1$ -c $ARG2$
#command[check_disk]=/usr/lib/nagios/plugins/check_disk -w $ARG1$ -c $ARG2$ -p $ARG3$
#command[check_procs]=/usr/lib/nagios/plugins/check_procs -w $ARG1$ -c $ARG2$ -s $ARG3$

#
# local configuration:
# if you'd prefer, you can instead place directives here
include=/etc/nagios/nrpe_local.cfg

#
# you can place your config snipplets into nrpe.d/
# only snipplets ending in .cfg will get included
include_dir=/etc/nagios/nrpe.d/

[benningtonr]

any ideas about this one?

[benningtonr]

had another Ubuntu server do the same thing, 4% available, and still only receiving warning, not critical alerts.

[scottwilkerson]

first off, you need to change this setting

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dont_blame_nrpe=0

should be

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dont_blame_nrpe=1

Also, can you post the file in /etc/nagios/nrpe.d/ which will contain your commands