[CentOS] Fan speed control on Supermicro X8DAL board with CentOS

Sun Feb 6 17:15:33 UTC 2011
Chuck Munro <chuckm at seafoam.net>

On Sun, 06 Feb 2011 12:09:12 +0000  Ned Slider wrote:
> On 06/02/11 07:00, Chuck Munro wrote:
>> > Hello folks,
>> >
>> > I'm having a difficult time trying to figure out why the CPU cooling
>> > fans run at full speed on my Supermicro X8DAL-3 motherboard.  There
>> > doesn't seem to be any variable speed (the fans are PWM compatible) ...
>> > they either idle at almost nothing, or suddenly burst into a
>> > high-pitched scream that gets my ears bleeding after a few seconds.
>> > Once they jump to warp-10, they remain there.
>> >
>> > The "Super-I/O" chip on this board is a Winbond W83627DHG which does the
>> > temperature and voltage monitoring.
>> >
>> > Is anyone aware of which driver or kernel module I need for that chip in
>> > order to get control of the fans?  The Supermicro web site and the
>> > board's manual aren't any help.  Fresh installs of CentOS-5.5 and RHEL-6
>> > don't exert any control by default.  Installing the lm_sensors package
>> > and probing with the 'sensors' command didn't help either.
>> >
>> > Slowly going deaf .......
>> >
>> > Chuck
> Hi Chuck,
> The correct kernel module for your chipset is w83627ehf.ko. I'm not sure
> the driver actually controls fan speed, I thought it was more for
> monitoring (fan speeds, temps, voltages) but I could be wrong. My
> current system (not a Supermicro) controls variable fan speed from
> options within the BIOS. I can enable/disable fan speed control and
> select either voltage or PWM based control.
> The stock w83627ehf driver in RHEL5.5 is oldish (they were updated in
> 5.5 I think but are still over a year old now). ELRepo.org have an
> updated driver available (kmod-w83627ehf) based on a backport from
> kernel-2.6.34. I've just checked upstream and a few more patches have
> been committed since kernel-2.6.34 and the current kernel-2.6.37 so I'll
> look at updating the elrepo driver with those latest patches.
> Hope that helps.
Thanks Ned!  I did go through the board's BIOS menus several times and 
could find only one fan control option, which ranges from always-fast 
for maximum performance to almost-silent for workstation use.  No matter 
what the setting, the fans may start out slow but eventually jump to 
high speed.  Updating the BIOS to the latest version made no difference. 
  I also noticed that at all times the BIOS reports the CPU temperatures 
as "Low" no matter what the fan speed.  The coolers are always cold to 
the touch.

I sure hope I don't have a defective board ... it's a royal pain to have 
to remove one from a large server.  I booted Ubuntu but the live-CD 
version doesn't have a working 'fancontrol' utility.  I'd be tempted to 
install Ubuntu Server but I much prefer staying with CentOS and KVM to 
match all of the guest virtual machines it'll be running.

Time to go through the mobo manual with a fine-tooth comb.  :-)