Hi guys,

i got an old IBM T41-Notebook and the noise off the fan is pretty annoying.
So i adpated that HOWTO from the thinkwiki (thinkwiki.org/wiki/How_to_control_fan_speed) to BackTrack3.

First you need to load the necessary kernel-module via
modprobe -v ibm-acpi experimental=1
After that has been done you should be able to read many informations of your machine out of /proc/acpi/ibm.
For instance temperatures (check thinkwiki to be sure which temp represents which sensor in your machine)
bt ~ # cat /proc/acpi/ibm/thermal
temperatures:   51 50 36 52 25 -128 23 -128
or fanspeed
bt ~ # cat /proc/acpi/ibm/fan
status: enabled
speed: 2953
level: 2
commands: level <level> (<level> is 0-7, auto, disengaged)
commands: enable, disable
commands: watchdog <timeout> (<timeout> is 0 (off), 1-120 (seconds))
So now everything you have to do to change the fanspeed is a
echo level 2 > /proc/acpi/ibm/fan
where the "2" was just an example for the fanspeedlevel. Watch out that "0" stops the fan completely!! That could be dangerous so watch your temps!
watch cat /proc/acpi/ibm/thermal
. If you dont wanna take any risk switch to the "auto" level which is probably pretty noisy.

There is also a very nice script that controls your fans automaticially, you may get it from: thinkwiki.org/index.php?title=Code/tp-fancontrol&action=raw&ctype=application/octet-stream just save it as .sh and chmod +x it to make it executable. Run it with ./ and everything works fine as long as you have loaded the ibm-acpi kernelmodule and running that stuff as root which is the default case unter backtrack3

If you wanna remove the Kernelmodule for whatever reason just do a
rmmod ibm-acpi
and everything will become normal/noisy again... ^^

hope this helps somebody