Lm sensors

zh-CN:Lm sensors

Usage

Installation

Install the lm_sensors package from the official repositories.

Setup

Use sensors-detect to detect and generate a list of kernel modules:

# sensors-detect

This will create the /etc/conf.d/lm_sensors configuration file which is used by the sensors daemon to automatically load kernel modules on boot. Users are asked to probe for various hardware. The "safe" answers are the defaults, so just hitting Enter to all the questions will generally not cause any problems.

When the detection is finished, a summary of the probes is presented.

Example:

# sensors-detect

# sensors-detect revision 6170 (2013-05-20 21:25:22 +0200)

This program will help you determine which kernel modules you need
to load to use lm_sensors most effectively. It is generally safe
and recommended to accept the default answers to all questions,
unless you know what you're doing.

Some south bridges, CPUs or memory controllers contain embedded sensors.
Do you want to scan for them? This is totally safe. (YES/no): 
Module cpuid loaded successfully.
Silicon Integrated Systems SIS5595...                       No
VIA VT82C686 Integrated Sensors...                          No
VIA VT8231 Integrated Sensors...                            No
AMD K8 thermal sensors...                                   No
AMD Family 10h thermal sensors...                           No

...

Now follows a summary of the probes I have just done.
Just press ENTER to continue: 

Driver `coretemp':
  * Chip `Intel digital thermal sensor' (confidence: 9)

Driver `lm90':
  * Bus `SMBus nForce2 adapter at 4d00'
    Busdriver `i2c_nforce2', I2C address 0x4c
    Chip `Winbond W83L771AWG/ASG' (confidence: 6)

Do you want to overwrite /etc/conf.d/lm_sensors? (YES/no): 
ln -s '/usr/lib/systemd/system/lm_sensors.service' '/etc/systemd/system/multi-user.target.wants/lm_sensors.service'
Unloading i2c-dev... OK
Unloading cpuid... OK

Note: A systemd service is automatically enabled if users answer YES when asked if you want to to generate /etc/conf.d/lm_sensors. Answering YES also automatically starts the service.

Running sensors

Example running sensors:

$ sensors

coretemp-isa-0000
Adapter: ISA adapter
Core 0:       +35.0°C  (crit = +105.0°C)
Core 1:       +32.0°C  (crit = +105.0°C)

w83l771-i2c-0-4c
Adapter: SMBus nForce2 adapter at 4d00
temp1:        +28.0°C  (low  = -40.0°C, high = +70.0°C)
                       (crit = +85.0°C, hyst = +75.0°C)
temp2:        +37.4°C  (low  = -40.0°C, high = +70.0°C)
                       (crit = +110.0°C, hyst = +100.0°C)

Reading SPD values from memory modules (optional)

To read the SPD timing values from your memory modules, install i2c-tools from the official repositories. Once you have i2c-tools installed, you will need to load the eeprom kernel module.

# modprobe eeprom

Finally, you can view your memory information with decode-dimms.

Here is partial output from one machine:

$ decode-dimms

# decode-dimms version 5733 (2009-06-09 13:13:41 +0200)

Memory Serial Presence Detect Decoder
By Philip Edelbrock, Christian Zuckschwerdt, Burkart Lingner,
Jean Delvare, Trent Piepho and others


Decoding EEPROM: /sys/bus/i2c/drivers/eeprom/0-0050
Guessing DIMM is in                             bank 1

---=== SPD EEPROM Information ===---
EEPROM CRC of bytes 0-116                       OK (0x583F)
# of bytes written to SDRAM EEPROM              176
Total number of bytes in EEPROM                 512
Fundamental Memory type                         DDR3 SDRAM
Module Type                                     UDIMM

---=== Memory Characteristics ===---
Fine time base                                  2.500 ps
Medium time base                                0.125 ns
Maximum module speed                            1066MHz (PC3-8533)
Size                                            2048 MB
Banks x Rows x Columns x Bits                   8 x 14 x 10 x 64
Ranks                                           2
SDRAM Device Width                              8 bits
tCL-tRCD-tRP-tRAS                               7-7-7-33
Supported CAS Latencies (tCL)                   8T, 7T, 6T, 5T

---=== Timing Parameters ===---
Minimum Write Recovery time (tWR)               15.000 ns
Minimum Row Active to Row Active Delay (tRRD)   7.500 ns
Minimum Active to Auto-Refresh Delay (tRC)      49.500 ns
Minimum Recovery Delay (tRFC)                   110.000 ns
Minimum Write to Read CMD Delay (tWTR)          7.500 ns
Minimum Read to Pre-charge CMD Delay (tRTP)     7.500 ns
Minimum Four Activate Window Delay (tFAW)       30.000 ns

---=== Optional Features ===---
Operable voltages                               1.5V
RZQ/6 supported?                                Yes
RZQ/7 supported?                                Yes
DLL-Off Mode supported?                         No
Operating temperature range                     0-85C
Refresh Rate in extended temp range             1X
Auto Self-Refresh?                              Yes
On-Die Thermal Sensor readout?                  No
Partial Array Self-Refresh?                     No
Thermal Sensor Accuracy                         Not implemented
SDRAM Device Type                               Standard Monolithic

---=== Physical Characteristics ===---
Module Height (mm)                              15
Module Thickness (mm)                           1 front, 1 back
Module Width (mm)                               133.5
Module Reference Card                           B

---=== Manufacturer Data ===---
Module Manufacturer                             Invalid
Manufacturing Location Code                     0x02
Part Number                                     OCZ3G1600LV2G     

...

Using Sensor Data

Graphical Front-ends

There are a variety of front-ends for sensors data.

• xsensors - X11 interface to lm_sensors
• xfce4-sensors-plugin - A lm_sensors plugin for the Xfce panel
• conky - Conky is an advanced, highly configurable system monitor for X based on torsmo
• kdeutils-superkaramba - Superkaramba is a tool which gives posibility to create different widgets for KDE desktop. Check the karamba section on kde-look.org for examples of making karamba front-ends for sensors data.
• sensors-applet - applet for the GNOME Panel to display readings from hardware sensors, including CPU temperature, fan speeds and voltage readings.

sensord

There is an optional daemon called sensord (included with the lm_sensors package) which can log your data to a round robin database (rrd) and later visualize graphically. See the sensord man page for details.

Tip and Tricks

Adjusting Values

In some cases, the data displayed might be incorrect or users may wish to rename the output. Use cases include:

• Incorrect temperature values due to a wrong offset (i.e. temps are reported 20 C higher then actual).
• Users wish to rename the output of some sensors.
• The cores might be displayed in an incorrect order.

All of the above (and more) can be adjusted by overriding the package provides settings in /etc/sensors3.conf by creating /etc/sensors.d/foo wherein any number of tweaks will override the default values. It is recommended to rename 'foo' to the motherboard brand and model but this naming nomenclature is optional.

Note: Do not edit /etc/sensors3.conf directly since package updates will overwrite your changes.

Example 1. Adjusting Temperature Offsets

This is a real example on a Zotac ION-ITX-A-U motherboard. The coretemp values are off by 20 C (too high) and are adjusted down to Intel specs.

$ sensors

coretemp-isa-0000
Adapter: ISA adapter
Core 0:       +57.0°C  (crit = +125.0°C)
Core 1:       +55.0°C  (crit = +125.0°C)
...

Run sensors with the -u switch to see what options are available for each physical chip (raw mode):

$ sensors -u

coretemp-isa-0000
Adapter: ISA adapter
Core 0:
  temp2_input: 57.000
  temp2_crit: 125.000
  temp2_crit_alarm: 0.000
Core 1:
  temp3_input: 55.000
  temp3_crit: 125.000
  temp3_crit_alarm: 0.000
...

Create the following file overriding the default values:

/etc/sensors.d/Zotac-IONITX-A-U

chip "coretemp-isa-0000"
  label temp2 "Core 0"
  compute temp2 @-20,@-20

  label temp3 "Core 1"
  compute temp3 @-20,@-20

Now invoking sensors shows the adjust values:

$ sensors

coretemp-isa-0000
Adapter: ISA adapter
Core 0:       +37.0°C  (crit = +105.0°C)
Core 1:       +35.0°C  (crit = +105.0°C)
...

Example 2. Renaming Labels

This is a real example on an Asus A7M266. The user wishes more verbose names for the temperature labels 'temp1' and 'temp2':

$ sensors

as99127f-i2c-0-2d
Adapter: SMBus Via Pro adapter at e800
...
temp1:        +35.0°C  (high =  +0.0°C, hyst = -128.0°C)
temp2:        +47.5°C  (high = +100.0°C, hyst = +75.0°C)
...

Create the following file to override the default values:

/etc/sensors.d/Asus_A7M266

chip "as99127f-*"
  label temp1 "Mobo Temp"
  label temp2 "CPU0 Temp"

Now invoking sensors shows the adjust values:

$ sensors

as99127f-i2c-0-2d
Adapter: SMBus Via Pro adapter at e800
...
Mobo Temp:        +35.0°C  (high =  +0.0°C, hyst = -128.0°C)
CPU0 Temp:        +47.5°C  (high = +100.0°C, hyst = +75.0°C)
...

Example 3. Renumbering Cores for Multi-CPU Systems

This is a real example on an HP Z600 workstation with dual Xeons. The actual numbering of physical cores is incorrect: numbered 0, 1, 9, 10 which is repeated into the second CPU. Most users expect the core temperatures to report out in sequential order, i.e. 0,1,2,3,4,5,6,7.

$ sensors

coretemp-isa-0000
Adapter: ISA adapter
Core 0:       +65.0°C  (high = +85.0°C, crit = +95.0°C)
Core 1:       +65.0°C  (high = +85.0°C, crit = +95.0°C)
Core 9:       +66.0°C  (high = +85.0°C, crit = +95.0°C)
Core 10:      +66.0°C  (high = +85.0°C, crit = +95.0°C)

coretemp-isa-0004
Adapter: ISA adapter
Core 0:       +54.0°C  (high = +85.0°C, crit = +95.0°C)
Core 1:       +56.0°C  (high = +85.0°C, crit = +95.0°C)
Core 9:       +60.0°C  (high = +85.0°C, crit = +95.0°C)
Core 10:      +61.0°C  (high = +85.0°C, crit = +95.0°C)
...

Again, run sensors with the -u switch to see what options are available for each physical chip:

$ sensors -u coretemp-isa-0000

coretemp-isa-0000
Adapter: ISA adapter
Core 0:
  temp2_input: 61.000
  temp2_max: 85.000
  temp2_crit: 95.000
  temp2_crit_alarm: 0.000
Core 1:
  temp3_input: 61.000
  temp3_max: 85.000
  temp3_crit: 95.000
  temp3_crit_alarm: 0.000
Core 9:
  temp11_input: 62.000
  temp11_max: 85.000
  temp11_crit: 95.000
Core 10:
  temp12_input: 63.000
  temp12_max: 85.000
  temp12_crit: 95.000

$ sensors -u coretemp-isa-0004

coretemp-isa-0004
Adapter: ISA adapter
Core 0:
  temp2_input: 53.000
  temp2_max: 85.000
  temp2_crit: 95.000
  temp2_crit_alarm: 0.000
Core 1:
  temp3_input: 54.000
  temp3_max: 85.000
  temp3_crit: 95.000
  temp3_crit_alarm: 0.000
Core 9:
  temp11_input: 59.000
  temp11_max: 85.000
  temp11_crit: 95.000
Core 10:
  temp12_input: 59.000
  temp12_max: 85.000
  temp12_crit: 95.000
...

Create the following file overriding the default values:

/etc/sensors.d/HP_Z600

chip "coretemp-isa-0000"
  label temp2 "Core 0"
  label temp3 "Core 1"
  label temp11 "Core 2"
  label temp12 "Core 3"

chip "coretemp-isa-0004"
  label temp2 "Core 4"
  label temp3 "Core 5"
  label temp11 "Core 6"
  label temp12 "Core 7"

Now invoking sensors shows the adjust values:

$ sensors

coretemp-isa-0000
Adapter: ISA adapter
Core0:        +64.0°C  (high = +85.0°C, crit = +95.0°C)
Core1:        +63.0°C  (high = +85.0°C, crit = +95.0°C)
Core2:        +65.0°C  (high = +85.0°C, crit = +95.0°C)
Core3:        +66.0°C  (high = +85.0°C, crit = +95.0°C)

coretemp-isa-0004
Adapter: ISA adapter
Core4:        +53.0°C  (high = +85.0°C, crit = +95.0°C)
Core5:        +54.0°C  (high = +85.0°C, crit = +95.0°C)
Core6:        +59.0°C  (high = +85.0°C, crit = +95.0°C)
Core7:        +60.0°C  (high = +85.0°C, crit = +95.0°C)
...

Automatic lm_sensors Deployment

If users wishing to deploy lm-sensors on multiple machines can use either of the following:

1. Accept defaults to questions:

# yes "" | sensors-detect

2. Override defaults and answer YES to all questions:

 # yes | sensors-detect

K10Temp Module

Some K10 processors have issues with their temperature sensor. From the kernel documentation (linux-<version>/Documentation/hwmon/k10temp):

All these processors have a sensor, but on those for Socket F or AM2+, the sensor may return inconsistent values (erratum 319). The driver will refuse to load on these revisions unless you specify the force=1 module parameter.

Due to technical reasons, the driver can detect only the mainboard's socket type, not the processor's actual capabilities. Therefore, if you are using an AM3 processor on an AM2+ mainboard, you can safely use the force=1 parameter.

On affected machines the module will report "unreliable CPU thermal sensor; monitoring disabled". If you still want to use the module you can:

# rmmod k10temp
# modprobe k10temp force=1

Confirm with Lm_sensors#Testing your lm_sensors that the sensor is in fact valid and reliable. If it is, you can edit /etc/modprobe.d/k10temp.conf and add:

options k10temp force=1

This will allow the module to load at boot.

Sensors not working since Linux 2.6.31

A change in version 2.6.31 has made some sensors stop working. See this FAQ entry for a detailed explanation and for some example errors. To fix sensors, add the following kernel parameters:

acpi_enforce_resources=lax

Warning: In some situations, this may be dangerous. Consult the FAQ for details.

Note that in most cases the information is still accessible via other modules (e.g. via ACPI modules) for the hardware in question. Many utilities and monitors (e.g. /usr/bin/sensors) can gather information from either source. Where possible, this is the preferred solution.