lm_sensors (Linux-monitoring sensors), is a free open source tool for Linux that provides tools and drivers for monitoring temperatures, voltage, humidity, and fans. It can also detect chassis intrusions. In this article we will install it and monitor CPU temperature using different commands.
1- Install EPEL Release if CentOS or RHEL
dnf install -y epel-release
2- Install Linux Monitoring Sensors
Install lm sensor on RHEL 8 and CentOS 8 and Fedora
dnf install -y lm_sensors
Install lm sensor on RHEL 7 and CentOS 7
yum install -y lm_sensors
If you are using Debian or Ubuntu use following command
sudo apt-get install lm-sensors
3- Sensor Configuration
Now, we need to make some configuration using below command after lm sensor installation. So if you want to go with default configuration simply hit enter key step by step.
sensors-detect
You will see similar steps during configuration.
[root@osradar ~]# sensors-detect sensors-detect revision 3.4.0-8 (2016-06-01) System: Hewlett-Packard HP Compaq dc7900 Small Form Factor Board: Hewlett-Packard 3031h Kernel: 3.10.0-957.27.2.el7.x86_64 x86_64 Processor: Intel(R) Core(TM)2 Duo CPU E8400 @ 3.00GHz (6/23/10) 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): 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 AMD Family 11h thermal sensors… No AMD Family 12h and 14h thermal sensors… No AMD Family 15h thermal sensors… No AMD Family 16h thermal sensors… No AMD Family 17h thermal sensors… No AMD Family 15h power sensors… No AMD Family 16h power sensors… No Intel digital thermal sensor… Success! (driver `coretemp') Intel AMB FB-DIMM thermal sensor… No Intel 5500/5520/X58 thermal sensor… No VIA C7 thermal sensor… No VIA Nano thermal sensor… No Some Super I/O chips contain embedded sensors. We have to write to standard I/O ports to probe them. This is usually safe. Do you want to scan for Super I/O sensors? (YES/no): Probing for Super-I/O at 0x2e/0x2f Trying familyNational Semiconductor/ITE'... Yes Found unknown chip with ID 0x1911 Probing for Super-I/O at 0x4e/0x4f Trying family
National Semiconductor/ITE'… No Trying family `SMSC'… Yes Found unknown chip with ID 0x0b00 Some systems (mainly servers) implement IPMI, a set of common interfaces through which system health data may be retrieved, amongst other things. We first try to get the information from SMBIOS. If we don't find it there, we have to read from arbitrary I/O ports to probe for such interfaces. This is normally safe. Do you want to scan for IPMI interfaces? (YES/no): Probing forIPMI BMC KCS' at 0xca0... No Probing for
IPMI BMC SMIC' at 0xca8… No Some hardware monitoring chips are accessible through the ISA I/O ports. We have to write to arbitrary I/O ports to probe them. This is usually safe though. Yes, you do have ISA I/O ports even if you do not have any ISA slots! Do you want to scan the ISA I/O ports? (YES/no): Probing forNational Semiconductor LM78' at 0x290... No Probing for
National Semiconductor LM79' at 0x290… No Probing forWinbond W83781D' at 0x290... No Probing for
Winbond W83782D' at 0x290… No Lastly, we can probe the I2C/SMBus adapters for connected hardware monitoring devices. This is the most risky part, and while it works reasonably well on most systems, it has been reported to cause trouble on some systems. Do you want to probe the I2C/SMBus adapters now? (YES/no): Sorry, no supported PCI bus adapters found. Module i2c-dev loaded successfully. Next adapter: i915 gmbus ssc (i2c-0) Do you want to scan it? (yes/NO/selectively): Next adapter: i915 gmbus vga (i2c-1) Do you want to scan it? (yes/NO/selectively): Next adapter: i915 gmbus panel (i2c-2) Do you want to scan it? (yes/NO/selectively): Next adapter: i915 gmbus dpc (i2c-3) Do you want to scan it? (yes/NO/selectively): Next adapter: i915 gmbus dpb (i2c-4) Do you want to scan it? (yes/NO/selectively): Next adapter: i915 gmbus dpd (i2c-5) Do you want to scan it? (yes/NO/selectively): 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) Do you want to overwrite /etc/sysconfig/lm_sensors? (YES/no): Unloading i2c-dev… OK [root@osradar ~]#
So, you will see similar screen upon successful configuration.
4- See CPU Temperature
Finally issue following command to see CPU temperature,
sensors
So, you can see in above image the command “sensors” is showing number of CPU cores its current temperature. But in brackets its is also showing high and critical temperatures in degree centigrade.
See temperature on Runtime
watch sensors
Check temperature in Fahrenheit
Then, what if you wanna see it in Fahrenheit, if you want to do so simply run below command.
sensors -f
That’s it.