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SENSORSD.CONF(5) File Formats Manual SENSORSD.CONF(5)

sensorsd.confconfiguration file for sensorsd

The sensorsd.conf file is read by sensorsd(8) to configure hardware sensor monitoring. Each variable in the sysctl(2) hw.sensors subtree represents a sensor. Each sensor is matched by at most one entry in sensorsd.conf, which may specify high and low limits, and whether sensor status changes provided by the driver should be ignored. Each time the limits are crossed in either direction or the status provided by the driver changes, sensorsd(8)'s alert functionality is triggered and a command, if specified, is executed.

sensorsd.conf follows the syntax of configuration databases as documented in cgetent(3). Sensors may be specified by their full hw.sensors sysctl(8) variable name or by type, with the full name taking precedence. For example, if an entry “hw.sensors.lm0.temp1” is not found, then an entry for “temp” will instead be looked for.

The following attributes may be used:

Specify a command to be executed on state change.
Specify the largest acceptable value.
Specify the smallest acceptable value.
Ignore status provided by the driver.

The values for temperature sensors can be given in degrees Celsius or Fahrenheit, for voltage sensors in volts, and fan speed sensors take a unit-less number representing RPM. For Boolean sensors, specify 0 for "Off" or 1 for "On". Values for all other types of sensors can be specified in the same units as they appear under the sysctl(8) hw.sensors tree.

Sensors that provide status (such as those from bio(4), esm(4), or ipmi(4)) do not require boundary values specified and simply trigger on status transitions. If boundaries are specified nonetheless, then they are used in addition to automatic status monitoring, unless the “istatus” attribute is specified to ignore status values that are provided by the drivers.

The command is executed when there is any change in sensor state. Tokens in the command are substituted as follows:

%l
Whether the value exceeds or is within the user specified limits. Can be one of: "below", "above", "within", "invalid", or "uninitialised".
%n
The sensor number.
%s
The sensor status.
%x
The xname of the device the sensor sits on.
%t
The type of sensor.
%2
The sensor's current value.
%3
The sensor's low limit.
%4
The sensor's high limit.

For Boolean sensors, %2, %3, and %4 are substituted with "On" or "Off".

By default, sensorsd(8) monitors status changes on all sensors that keep their state. This behaviour may be altered by using the “istatus” attribute to ignore status changes of sensors of a certain type or individual sensors.

/etc/sensorsd.conf
Configuration file for sensorsd(8).
/etc/examples/sensorsd.conf
Example configuration file.

In the following configuration file, if hw.sensors.ipmi0.temp0 moves upwards beyond 80C or downwards to 80C or less or if its status as provided by ipmi(4) changes, the command /etc/sensorsd/log_warning will be executed, with the sensor type, number and current value passed to it. Alerts will be sent if hw.sensors.lm0.volt3 moves into or out of the range from 4.8V to 5.2V, inclusive; if the speed of the fan attached to hw.sensors.lm0.fan1 transitions to being below or above 1000RPM; if any RAID volume drive changes its status from, for example, “OK”, such as in the case of drive failure, rebuild, or a complete failure, the command /etc/sensorsd/drive will be executed, with the sensor number passed to it; however, no alerts will be generated for status changes on timedelta sensors. For all other sensors whose drivers automatically provide sensor status updates, alerts will be generated each time those sensors undergo status transitions.

# Comments are allowed
hw.sensors.ipmi0.temp0:high=80C:command=/etc/sensorsd/log_warning %t %n %2
hw.sensors.lm0.volt3:low=4.8V:high=5.2V
hw.sensors.lm0.fan1:low=1000
drive:command=/etc/sensorsd/drive %n
timedelta:istatus	#ignore status changes for timedelta

cgetent(3), bio(4), ipmi(4), sensorsd(8), sysctl(8)

The sensorsd.conf file format first appeared in OpenBSD 3.5. The format was altered in OpenBSD 4.1 to accommodate hierarchical device-based sensor addressing. The “istatus” attribute was introduced in OpenBSD 4.2.

Alert functionality is triggered every time there is a change in sensor state; for example, when sensorsd(8) is started, the status of each monitored sensor changes from undefined to whatever it is. One must keep this in mind when using commands that may unconditionally perform adverse actions (e.g. shutdown(8)), as they will be executed even when all sensors perform to specification. If this is undesirable, then a wrapper shell script should be used instead.

February 10, 2020 OpenBSD-7.3