UDM Fan control speed


I've also installed the netdata docker/podman. It shows me the actual fan speeds and temps in a graph. It helped me a lot to solve this issue.

podman run --privileged -d --name=netdata --restart always \
 --net="host" \
 --pid="host" \
 -v netdatalib:/var/lib/netdata \
 -v netdatacache:/var/cache/netdata \
 -v /etc/passwd:/host/etc/passwd:ro \
 -v /etc/group:/host/etc/group:ro \
 -v /proc:/host/proc:ro \
 -v /sys:/host/sys:ro \
 -v /etc/os-release:/host/etc/os-release:ro \
 --cap-add SYS_PTRACE \
 --security-opt apparmor=unconfined \

Fan1 = CPU fan = pwm2
Fan2 = Disk 40mm fan = pwm1
The CPU fan can't be fully stopped. It wil always run minimal at ~800 rpm.
The disk fan can be fully stopped. It wil obviously show 0 rpm when stopped.

The CPU fan minimum start offset is "77" and is ~800 rpm .
The disk fan minimum start offset is "35" and is ~800 rpm (if you would like to keep it running for airflow).

CPU fan:
echo 77 >/sys/class/hwmon/hwmon0/device/pwm2

Disk fan:
echo 35 >/sys/class/hwmon/hwmon0/device/pwm1

Making this survive a reboot does indeed need the on-boot-script. I've made a simple script which surives a reboot:

Install on-boot-script
Make a file with VI called "11-set-fan-speed.sh" in /mnt/data/onboot.d/
Make the boot script executable chmod +x /mnt/data/on
Reboot and enjoy the silence


echo 77 >/sys/class/hwmon/hwmon0/device/pwm2
echo 35 >/sys/class/hwmon/hwmon0/device/pwm1
I can confirm that it DOES survive a reboot. Got it working on 1.8.5. Display also shows correct values. Running stable at 44 degrees Celsius on CPU and 41 degrees Celsius board-temp.