I wrote this because my R730xd's fans run high with 3rd party drives. This is a known issue that Dell won't fix (probably to sell drives). This uses the IPMI interface to control the fan speed.

1. Run the fans as quiet as possible to maintain a specific system temperature
2. React continuously to load (i.e. not just at a static percentage) smoothly to avoid spiking the fans when not needed, but also without letting things get too hot.
3. Be conservative and restore the system-managed fans any time anything fails
4. Maintain a minimum fan speed to move air through the system

This is a single python script and a YAML file for config. It uses a simple PID controller algorithm to try to find the fan speed that will keep temperatures at a specific point. Above that point and it will run fans to try to get it down to the desired point. Below and it will assume no (additional) cooling is needed.

You need IPMI local and ipmitool installed to work. You also need the simple_pid python module installed.

$ sudo python3 -mpip install simple_pid
$ curl -O https://raw.githubusercontent.com/kk7ds/dellfancontrol/master/fancontrol.py
$ curl -O https://raw.githubusercontent.com/kk7ds/dellfancontrol/master/fancontrol.yaml
$ chmod +x fancontrol.py

Review the settings available in the YAML file and then run the script:

$ sudo ./fancontrol.py --config fancontrol.yaml --debug

Whenever the script runs, it will put the fan controller into manual mode and control the speed. Whenever the script exits, it will restore system-managed mode for safety. If the script fails, is killed, or detects that any of the panic_temps sensors are over limit, it will place the fans back into system-managed mode.

After tuning, you can run without --debug for less-verbose output.

PID tuning is a black art. See the plethora of available articles on the topic that google has to offer. The default kp, ki, and kd values work well for me, but my machine runs in a stable, cool room with very predictable load.

This script makes every effort to fail into a safe situation, but no OS-based approach can truly do this perfectly. Use this with caution, monitor things closely, and know that you accept all the risk that comes from using this!