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Check sensors-fans

Overview

Reports hardware fan speeds in RPM (rounds per minute). Returns OK if no fans are detected.

Important Notes:

  • Run sensors-detect --auto beforehand to scan the system for hardware monitoring chips supported by libsensors / lm_sensors

Data Collection:

  • Uses psutil.sensors_fans() to read fan speed data from hardware sensors

Fact Sheet

Fact Value
Check Plugin Download https://github.com/Linuxfabrik/monitoring-plugins/tree/main/check-plugins/sensors-fans
Nagios/Icinga Check Name check_sensors_fans
Check Interval Recommendation Every minute
Can be called without parameters Yes
Runs on Cross-platform
Compiled for Windows No
3rd Party Python modules psutil

Help

usage: sensors-fans [-h] [-V] [--always-ok] [-c CRIT] [--test TEST] [-w WARN]

Reports hardware fan speeds in RPM (rounds per minute). Alerts when fan speeds
fall outside the thresholds reported by the hardware sensors.

options:
  -h, --help           show this help message and exit
  -V, --version        show program's version number and exit
  --always-ok          Always returns OK.
  -c, --critical CRIT  CRIT threshold for fan speed, in RPM. Default: 20000
  --test TEST          For unit tests. Needs "path-to-stdout-file,path-to-
                       stderr-file,expected-retc".
  -w, --warning WARN   WARN threshold for fan speed, in RPM. Default: 10000

Usage Examples

./sensors-fans --warning 10000 --critical 20000

Output:

dell_smm: dell_smm = 4714 RPM, dell_smm = 4428 RPM

States

  • OK if all fan speeds are below the warning threshold or if no fans are detected.
  • WARN if any fan speed meets or exceeds --warning (default: 10000 RPM).
  • CRIT if any fan speed meets or exceeds --critical (default: 20000 RPM).
  • UNKNOWN if the platform is not supported by psutil.
  • --always-ok suppresses all alerts and always returns OK.

Perfdata / Metrics

Name Type Description
{sensor_name}_{label} Number Fan speed in RPM, one metric per fan sensor.

Troubleshooting

Python module "psutil" is not installed.
Install psutil: pip install psutil or dnf install python3-psutil.

Credits, License