Nagios CPU mpstat Plugin

Project Notes

check_cpu_mpstat.sh is a Bash plugin for Nagios, Centreon, and other compatible monitoring platforms. It checks CPU usage statistics — specifically user, system, and iowait percentages — using the mpstat command from the sysstat package, which provides improved accuracy and multi-core compatibility over older tools like iostat and vmstat.

This script is based on the original check_cpu.sh plugin by Andreas Baess, but replaces vmstat with mpstat, adds robust argument parsing, per-category thresholds, and better compatibility with modern Linux systems.

???? Features
Uses mpstat for accurate CPU sampling, supporting multi-core systems

Configurable thresholds per category: user, system, iowait

Compatible with Nagios, Centreon, and other Nagios-style monitoring systems

Outputs performance data for graphing

Customizable sampling interval and number of samples

Returns standard Nagios exit codes (OK, WARNING, CRITICAL, UNKNOWN)

???? Requirements
mpstat (usually provided by the sysstat package)

Bash (tested with GNU Bash 4+)

?? Example Usage
./check_cpu_mpstat.sh -uw 70 -uc 90 -sw 60 -sc 85 -iw 40 -ic 60 -i 1 -n 1
???? Arguments
Flag Description
-uw Warning threshold for user CPU (%)
-uc Critical threshold for user CPU (%)
-sw Warning threshold for system CPU (%)
-sc Critical threshold for system CPU (%)
-iw Warning threshold for iowait CPU (%)
-ic Critical threshold for iowait CPU (%)
-i Interval between samples (seconds)
-n Number of samples to average
-h Help output

???? Example Output
CPU OK: user=12% system=5% iowait=1% idle=82% | cpu_user=12%;70;90; cpu_sy

???? Credits
Original idea and structure by Andreas Baess
Original plugin: check_cpu.sh