Setting temperature thresholds in i8kmon Ubuntu 14.04

Question

I have an overheating problem with my Dell Inspiron 15R and installed i8kmon to control the fan speeds on Ubuntu 14.04.

Here is a copy of the 'lm-sensors' output:

coretemp-isa-0000
Adapter: ISA adapter
Physical id 0:  +62.0°C  (high = +87.0°C, crit = +105.0°C)
Core 0:         +57.0°C  (high = +87.0°C, crit = +105.0°C)
Core 1:         +61.0°C  (high = +87.0°C, crit = +105.0°C)

i8k-virtual-0
Adapter: Virtual device
Right Fan:      0 RPM
CPU:          +62.0°C 

Even when setting the temperature thresholds in /etc/i8kmon to:

set config(daemon)      1

# Automatic fan control, override with --auto option
set config(auto)        1

# Report status on stdout, override with --verbose option
set config(verbose) 1

# Status check timeout (seconds), override with --timeout option
set config(timeout) 1

# Temperature thresholds: {fan_speeds low_ac high_ac low_batt high_batt}
set config(0)   {{0 -}  -1  55  -1  55}
set config(1)   {{1 -}  55  70  55  70}
set config(2)   {{2 -}  60  128  60  128}

The fan does not start when it should. Any ideas of what might be wrong ? Here is a copy of the log when running i8kmon manually with the --verbose option:

i8kmon v1.30 11/16/2013 - Copyright (C) 2013 Vitor Augusto <vitorafsr@gmail.com>
config(0)          = {0 0} -1 60 -1 65
config(1)          = {1 0} 50 70 55 75
config(2)          = {1 1} 60 80 65 85
config(3)          = {2 2} 70 128 75 128
config(acpi)       = acpi
config(auto)       = 1
config(daemon)     = 1
config(geometry)   = 
config(i8kfan)     = /usr/bin/i8kfan
config(min_speed)  = 2000
config(sysconfig)  = /etc/i8kmon.conf
config(t_high)     = 80
config(timeout)    = 5
config(unit)       = C
config(use_conf)   = 1
config(userconfig) = ~/.i8kmon
config(verbose)    = 1
status(ac)         = 0
status(acpi_timer) = 0
status(left)       = 
status(leftspeed)  = 0 -1 -1 -1
status(lspeed)     = 0
status(lstate)     = 0
status(lstuck)     = 0
status(nfans)      = 2
status(right)      = 
status(rightspeed) = 0 0 0 0
status(rspeed)     = 0
status(rstate)     = 2
status(rstuck)     = 0
status(state)      = 0
status(t_high)     = 0
status(t_low)      = 0
status(temp)       = 0
status(timer)      = 
status(ui)         = 0
1410467738 acpi: Battery 0: Discharging, 89%, 03:13:17 remaining
temp, left, right, ac state: 60 -1 2 0
# exec /usr/bin/i8kfan 0 0
temp, left, right, ac state: 59 -1 0 0
# exec /usr/bin/i8kfan 0 {}
temp, left, right, ac state: 58 -1 0 0
# exec /usr/bin/i8kfan 0 {}
temp, left, right, ac state: 58 -1 0 0
# exec /usr/bin/i8kfan 0 {}
temp, left, right, ac state: 60 -1 0 0
# exec /usr/bin/i8kfan 0 {}
temp, left, right, ac state: 58 -1 0 0
# exec /usr/bin/i8kfan 0 {}
temp, left, right, ac state: 59 -1 0 0
# exec /usr/bin/i8kfan 0 {}
temp, left, right, ac state: 58 -1 0 0
# exec /usr/bin/i8kfan 0 {}
temp, left, right, ac state: 58 -1 0 0
# exec /usr/bin/i8kfan 0 {}
temp, left, right, ac state: 60 -1 0 0

It seems that the temperatures are wrong and i8kmon is not turning on the fan.

Answer 1

According to lm-sensors:

i8k-virtual-0
Adapter: Virtual device
Right Fan:      0 RPM

You have a only Right Fan, thus left fan values should always be -1. You have to change your set config, in the file /etc/i8kmon.conf, to the following values:

set config(0)   {{-1 0}  -1  40  -1  40}
set config(1)   {{-1 1}  40  60  40  60}
set config(2)   {{-1 2}  60  128  60  128}
set config(3)   {{-1 2}  60  128  60  128}

in the state {-1 0}, there is no left-fan and the right-fan is off, in state {-1 1}, the right-fan should run at low speed while in the state {-1 2} it should run at full speed. The other values, e.g. 40 60 40 60, correspond to the temperature thresholds ---min and max--- of each state, with and without AC-power.

You also need to add the following options:

# Run as daemon, override with --daemon option
set config(daemon)      0

# Automatic fan control, override with --auto option
set config(auto)        1

# Report status on stdout, override with --verbose option
set config(verbose) 1

# Status check timeout (seconds), override with --timeout option
set config(timeout) 20

Finally, you need to create the file i8k.conf in /etc/modprobe.d/ containing the line options i8k force=1.

See more details man i8kmon