Minimalist Linux fan control designed to be simple and powerful.
Linux hardware monitoring hwmon exposes temperature measurements and fan controls as files in sysfs. An ideal fan control application would:
- Obtain temperature measurements by reading from the sensor files.
- Control fan speeds by writing into fan speed control files.
- Minimize its own CPU and RAM resource usage. One process with one thread is the ideal.
- Be robust against hardware changes. Plugging in a USB device must not break the fan control application.
- Be as simple as possible.
To achieve its design objectives zen-fan:
- Is written in plain
bashusing version 4 features. No compilation is required. - Doesn't invoke any other executables and doesn't depend on any other software.
- Doesn't spawn any processes/threads on each iteration.
Empirical average CPU time of one iteration is under 27 milliseconds, resident size is under 4MB.
zen-fan was inspired by fancontrol. Unlike fancontrol,zen-fan:
- Doesn't fail to start when hardware changes, a USB device is plugged-in/out.
- Doesn't crash when fans have been adjusted by another application.
- Doesn't spawn new processes on each iteration.
Configuration is stored in zen-fan.d directory. Use host.supernova.cfg as an example.
Copy and modify an existing configuration file to suit your machine and test it. E.g.:
cd zen-fan
cp zen-fan.d/host.supernova.cfg zen-fan.d/host.$HOSTNAME.cfg # Modify zen-fan.d/host.$HOSTNAME.cfg to suit your machine
sudo -E ./zen-fan.sh # Loads zen-fan.d/host.$HOSTNAME.cfg
Once your configuration is ready, you can run zen-fan from the source directory as is:
cd zen-fan
sudo -E ./zen-fan.sh
Once your configuration is ready, you may like to install zen-fan as systemd service:
cd zen-fan
sudo ./install.zen-fan.service.sh
systemctl --no-pager status zen-fan
● zen-fan.service - zen-fan fan control service
Loaded: loaded (/etc/systemd/system/zen-fan.service; enabled; vendor preset: enabled)
Active: active (running) since Tue 2023-05-30 01:06:51 BST; 8min ago
Main PID: 8327 (zen-fan)
Tasks: 2 (limit: 134671)
Memory: 972.0K
CPU: 27ms
CGroup: /system.slice/zen-fan.service
├─8327 /bin/bash /etc/systemd/system/zen-fan.service.d/zen-fan
└─8330 /bin/bash /etc/systemd/system/zen-fan.service.d/zen-fan
May 30 01:06:51 supernova zen-fan[8327]: k10temp is /sys/class/hwmon/hwmon3.
May 30 01:06:51 supernova zen-fan[8327]: corsaircpro is /sys/class/hwmon/hwmon4.
May 30 01:06:51 supernova zen-fan[8327]: CPU temperature sensor is k10temp hwmon3/temp1.
May 30 01:06:51 supernova zen-fan[8327]: GPU temperature sensor is corsaircpro hwmon4/temp3.
May 30 01:06:51 supernova zen-fan[8327]: Fans front corsaircpro hwmon4/fan1 hwmon4/fan2 hwmon4/fan3.
May 30 01:06:51 supernova zen-fan[8327]: Fans back corsaircpro hwmon4/fan4 hwmon4/fan5.
May 30 01:06:51 supernova zen-fan[8327]: CPU 46°C, GPU 45°C, hwmon4/fan1 599rpm, hwmon4/fan2 601rpm, hwmon4/fan3 600rpm, hwmon4/fan4 301r…an5 300rpm.
May 30 01:06:51 supernova zen-fan[8327]: CPU 46°C, GPU 45°C, front fans target 600rpm+, back fans target 300rpm+.
May 30 01:06:51 supernova zen-fan[8327]: Fan control loop started. Adjust fans every 7 seconds for -1 iterations.
journalctl --no-pager -u zen-fan -n 3
Example output:
May 30 01:06:51 supernova zen-fan[8327]: CPU 46°C, GPU 45°C, hwmon4/fan1 599rpm, hwmon4/fan2 601rpm, hwmon4/fan3 600rpm, hwmon4/fan4 301rpm, hwmon4/fan5 300rpm.
May 30 01:06:51 supernova zen-fan[8327]: CPU 46°C, GPU 45°C, front fans target 600rpm+, back fans target 300rpm+.
May 30 01:06:51 supernova zen-fan[8327]: Fan control loop started. Adjust fans every 7 seconds for -1 iterations.
sudo pkill -HUP zen-fan
Example output:
May 30 01:24:35 supernova zen-fan[8327]: CPU 43°C, GPU 44°C, hwmon4/fan1 600rpm, hwmon4/fan2 600rpm, hwmon4/fan3 601rpm, hwmon4/fan4 301rpm, hwmon4/fan5 300rpm.
sudo pkill -USR1 zen-fan
sudo pkill -USR2 zen-fan
Copyright (c) 2023 Maxim Egorushkin. MIT License. See the full licence in file LICENSE.