Dell R710 (and possibly other) temperature-based fan speeds script

updatefans.sh

#!/bin/bash

# Script for checking the temperature reported by the ambient temperature sensor,
# and if deemed too high send the raw IPMI command to enable dynamic fan control.
#
# Also get CPU temps from lm-sensors and adjust fan speeds according to defined
# speed % which should be set according to your needs (each CPU model will vary)
#
# Requires:
# ipmitool – apt install ipmitool
# sensors - apt install lm-sensors
# bc - apt install bc

LASTSPEED=$(cat /tmp/lastspeed 2>/dev/null || echo 0)

function setfans () {
  speed=$1
  if [[ $speed == "auto" ]]; then
    # Enable automatic fan speed control
    ipmitool raw 0x30 0x30 0x01 0x01 >/dev/null 2>&1 &
    LASTSPEED=${speed}
    echo "[$(date)] $(hostname) FANS: AUTO (SYS: ${SYSTEMP}C, CPU: ${CPUTEMP}C)"
    echo "AUTO (SYS: ${SYSTEMP}C, CPU: ${CPUTEMP}C)" | systemd-cat -t updatefans
  else
    speedhex=$(echo "obase=16; $speed" | bc)
    # Enable manual fan speed control
    if [[ "$LASTSPEED" == "auto" ]] || [[ "$LASTSPEED" == "0" ]]; then
      ipmitool raw 0x30 0x30 0x01 0x00 >/dev/null 2>&1 # &
    fi
    ipmitool raw 0x30 0x30 0x02 0xff 0x${speedhex} >/dev/null 2>&1 &
    LASTSPEED=${speed}
    echo "[$(date)] $(hostname) FANS: ${speed}% (0x${speedhex}) (SYS: ${SYSTEMP}C, CPU: ${CPUTEMP}C)"
    echo "${speed}% (0x${speedhex}) (SYS: ${SYSTEMP}C, CPU: ${CPUTEMP}C)" | systemd-cat -t updatefans
  fi
}

# This variable sends a IPMI command to get the temperature, and outputs it as two digits.
SYSTEMP=$(ipmitool sdr type temperature | grep Ambient | grep degrees | grep -Po '\d{2}' | tail -1)

#highest of all core temps
CPUTEMP=$(sensors | grep high | cut -d "+" -f2 | cut -d "." -f1 | sort -n | tail -1)

# Use the cpu temperature to calculate an optimal fan speed compared to the temperature using the formula x^2/50
let "SPEED=$CPUTEMP**2/50"

# Ceil the value
SPEED=$(echo $SPEED | awk '{print int($1+0.5)}')

if [[ $SYSTEMP > 32 || $CPUTEMP > 65 ]]; then
  echo   "Warning: SysTemp or CpuTemp too high! Activating dynamic fan control! ($SYSTEMP C)"
  echo "Warning: SysTemp or CpuTemp too high! Activating dynamic fan control! ($SYSTEMP C)" | systemd-cat -p "warning" -t updatefans
  setfans auto
else
  setfans $SPEED
fi

echo $LASTSPEED > /tmp/lastspeed

I modified this script to be ran using crontab and changed to using a formula to calculate the wanted fan speed, also changed it so that it uses the local ipmi instead of remote

it also echoes the settings to the journal, in case you would want to read it afterwards

See the fan calculation formula in desmos here: https://www.desmos.com/calculator/99xslq69vn

To install:

• Make sure all dependencies are installed (see the top of the script file) and make sure the script works on your hardware before making it automatically.

• Run sudo curl -o /usr/bin/updatefans.sh https://gist.githubusercontent.com/alvesvaren/85c8dd14077dee98925631425cad606f/raw && sudo chmod +x /usr/bin/updatefans.sh

• Test the script out by running /usr/bin/updatefans.sh

  • If you want to revert to automatic control: run sudo ipmitool raw 0x30 0x30 0x01 0x01

  • If everything works correctly, then just run sudo crontab -e and add this line to the file:

    * * * * * /usr/bin/updatefans.sh > /dev/null 2>&1
    

    This will run the script every 60 seconds, updating the fan speed each time

To view the log:

Run sudo journalctl -rt updatefans

To uninstall:

If you do not like it for any reason, you can delete the file at /usr/bin/updatefans.sh, remove it from the crontab and run sudo ipmitool raw 0x30 0x30 0x01 0x01 to enable the automatic fan bios based fancontrol.

This script is tested on R710 and R410 and seems to work fine on both

Thank you, i like your optimal fan speed calc

FYI, I had to run sudo chmod -t /tmp in order to get $LASTSPEED to save