A temperature-based fan speed controller for Dell servers (tested on an R710, should work with most PowerEdges). Supports both local and remote hosts.
- Python 3 is installed.
- IPMI Over LAN is enabled in all used iDRACs (Login > Network/Security > IPMI Settings).
- May not be needed if you're only managing the local machine.
lm-sensorsis installed and configured on the local machine.- Example output of
sensorsfor a dual CPU system:coretemp-isa-0000 Adapter: ISA adapter Core 0: +38.0°C (high = +69.0°C, crit = +79.0°C) Core 1: +46.0°C (high = +69.0°C, crit = +79.0°C) Core 2: +40.0°C (high = +69.0°C, crit = +79.0°C) Core 8: +43.0°C (high = +69.0°C, crit = +79.0°C) Core 9: +39.0°C (high = +69.0°C, crit = +79.0°C) Core 10: +39.0°C (high = +69.0°C, crit = +79.0°C) coretemp-isa-0001 Adapter: ISA adapter Core 0: +29.0°C (high = +69.0°C, crit = +79.0°C) Core 1: +35.0°C (high = +69.0°C, crit = +79.0°C) Core 2: +29.0°C (high = +69.0°C, crit = +79.0°C) Core 8: +34.0°C (high = +69.0°C, crit = +79.0°C) Core 9: +33.0°C (high = +69.0°C, crit = +79.0°C) Core 10: +31.0°C (high = +69.0°C, crit = +79.0°C)
- Example output of
Clone the repo and run the installation script as root to configure the system or upgrade the already installed controller:
git clone https://github.com/nmaggioni/r710-fan-controller.git
cd r710-fan-controller
sudo ./install.sh [<installation path>]
The default installation path is /opt/fan_control and the service will be installed as fan-control.service. If a configuration file already exists, it will be renamed with a .old extension.
To deploy remote fan management with Docker (fan_control running on a separate host and only interacting with remote ones, see Notes on remote hosts), build the image in the repo and bind mount your own YAML config and SSH keys folder:
docker build -t fan_control .
docker run -d --restart=always --name fan_control -v "./fan_control.yaml:/app/fan_control.yaml:ro" -v "./keys:/app/keys:ro" fan_controlRunning this tool under a proper orchestrator is advised.
You can tune the controller's settings via the fan_control.yaml file in the installation directory.
The file is made of two main sections, general and hosts. The first one contains global options; the second one, hosts, is a list of hosts to manage. Each of them must contain a temperatures and a speeds lists at a minimum, both of exactly three values. If the hysteresis key isn't specified, its value is assumed to be 0.
Remote hosts must also contain both the remote_temperature_command string and the remote_ipmi_credentials structure.
| Key | Description |
|---|---|
general.debug |
Toggle debug mode (print ipmitools commands instead of executing them, enable additional logging). |
general.interval |
How often (in seconds) to read the CPUs' temperatures and adjust the fans' speeds. |
hosts[n].hysteresis |
How many degrees (in °C) the CPUs' temperature must go below the threshold to trigger slowing the fans down. Prevents rapid speed changes, a good starting value can be 3. |
hosts[n].temperatures |
A list of three upper bounds (in °C) of temperature thresholds. See below for details. |
hosts[n].speeds |
A list of three speeds (in %) at which fans will run for the correspondent threshold. See below for details. |
hosts[n].remote_temperature_command |
For remote hosts only. A command that will be executed to obtain the temperatures of this remote system. See notes for details. |
hosts[n].remote_ipmi_credentials.host |
For remote hosts only. The iDRAC hostname/IP of this remote system. See notes for details. |
hosts[n].remote_ipmi_credentials.username |
For remote hosts only. The username used to login to this remote system's iDRAC. See notes for details. |
hosts[n].remote_ipmi_credentials.password |
For remote hosts only. The password used to login to this remote system's iDRAC. See notes for details. |
Every general.interval seconds the controller will fetch the temperatures of all the available CPU cores, average them and round the result (referred to as Tavg below). It will then follow this logic to set the fans' speed percentage or engage automatic (hardware managed) control.
| Condition | Fan speed |
|---|---|
| Tavg ≤ Threshold1 | Threshold1 |
| Threshold1 < Tavg ≤ Threshold2 | Threshold2 |
| Threshold2 < Tavg ≤ Threshold3 | Threshold3 |
| Tavg > Threshold3 | Automatic |
If hysteresis is set for a given host, the controller will wait for the temperature to go below ThresholdN - hysteresis temperature. For example: with a Threshold2 of 37°C and an hysteresis of 3°C, the fans won't slow down from Threshold3 to Threshold2 speed until the temperature reaches 34°C.
This controller can monitor the temperature and change the fan speed of remote hosts too: the only caveat is that you'll need to extract the temperatures via an external command. This could be via SSH, for example. The controller expects such a command to return a newline-delimited list of numbers parseable as floats.
The included example is a good fit for a remote FreeNAS host: it will connect to it via SSH and extract the temperature of all CPU cores, one per line. This way you'll be able to manage that machine just as well as the local one without applying any hardly trackable modification to the base OS.
Major thanks go to NoLooseEnds's directions for the core commands and sulaweyo's ruby script for the idea of automating them.
Note: The key difference of this script, other than handling remote hosts, is that it's based on the temperature of the CPUs' cores and not on the ambient temperature sensor on the server's motherboard. The R710 does not expose CPU temperature over IPMI, but other models do; this script should work with them nonetheless.