The time should be specified as a raw integer (seconds) or with a suffix `s' for seconds, `m' for minutes or `h' for hours; for example, the default interval is `60' or `1m'.
Specify an interval of zero to suppress scanning explicitly for alarms.
The time is specified as before; e.g., `30m'.
Specify an interval of zero to suppress logging of regular sensor readings.
The time is specified as before; e.g., `5m'.
See the section ROUND ROBIN DATABASES below for more details.
Other possible facilities include local0 through local7, and user.
A typical chip name would be `w83782d-*' (you may want to escape the `*' for your shell) which would scan any W83782D chips on any bus. See sensors.conf(5) for more details. Another option is to simply not load the sensor modules for chips in which you have no interest.
Upon receipt of a SIGHUP, this daemon will rescan the kernel interface for chips and features, and reload the libsensors configuration file.
Regular sensor readings are logged at the level info. Alarms are logged at the level alert. Inconsequential status messages are logged at the minimum level, debug, when debugging is enabled.
You can use an appropriate `/etc/syslog.conf' file to direct these messages in a useful manner. See syslog.conf(5) for full details. Assuming you set the logging facility to local4, the following is a sample configuration:
# Sample syslog.conf entries *.info;...;local4.none;local4.warn /var/log/messages local4.info -/var/log/sensors local4.alert /dev/console local4.alert *
The first line ensures that regular sensor readings do not clutter `/var/log/messages'; we first say `local4.none' to eliminate informational messages; then `local4.warn' to enable warnings and above. The second line says to log all regular sensor readings to `/var/log/sensors'; the leading hyphen `-' means that this file is not flushed after every message. The final two lines ensure that alarms are printed to the system console as well as to all connected users (in addition to `/var/log/messages' and `/var/log/sensors').
# Sample logrotate.d entry
/var/log/sensors {
postrotate
/usr/sbin/killall -HUP syslogd
endscript
}
Note, of course, that you want to restart syslogd(8) and not sensord(8)
Note that some drivers may lack support for alarm reporting even though the chips they support do have alarms. As of Linux 2.6.23, many drivers still don't report alarms in a format suitable for libsensors 3.
Round-robin databases are constant-size databases that can be used to store, for example, a week's worth of sensor readings. Subsequent readings stored in the database will overwrite readings that are over a week old. This capability is extremely useful because it allows useful information to be stored in an easily-accessible manner for a useful length of time, without the burden of ever-growing log files.
The rrdtool(1) utility and its associated library provide the basic framework for the round-robin database beneath sensord(8). In addition, the rrdcgi(1) and rrdgraph(1) utilities provide support for generating graphs of these data for display in a Web page.
If you wish to use the default configuration of round-robin database, which holds one week of sensor readings at five-minute intervals, then simply start sensord(8) and specify where you want the database stored. It will automatically be created and configured using these default parameters.
If you wish readings to be stored for a longer period, or want multiple readings to be averaged into each database entry, then you must manually create and configure the database before starting sensord(8). Consult the rrdcreate(1) manual for details. Note that the database must match exactly the names and order of sensors read by sensord(8). It is recommended that you create the default database and then use rrdinfo(1) to obtain this information, and/or rrdtune(1) to change it.
After creating the round-robin database, you must then configure your Web server to display the sensor information. This assumes that you have a Web server preconfigured and functioning on your machine. Sensord(8) provides a command-line option --rrd-cgi to generate a basic CGI script to display these graphs; you can then customize this script as desired. Consult the rrdcgi(1) manual for details. This CGI script requires a world-writable, Web-accessible directory into which to write the graphs that it generates.
An example of how to set up Web-accessible graphs of recent sensor readings follows:
sensord --log-interval 0 \ --load-average \ --rrd-file /var/log/sensord.rrd
Here, we start sensord(8) and configure it to store readings in a round-robin database; note that we disable logging of sensor readings to syslog(3), and enable logging of the load average.
mkdir /var/www/sensord chown www-data:staff /var/www/sensord chmod a=rwxs /var/www/sensord
Here, we create a world-writable, Web-accessible directory in which graphs will be stored; we set the ownership and permissions on this directory appropriately. You will have to determine the location and ownership that is appropriate for your machine.
sensord --load-average \ --rrd-file /var/log/sensord.rrd \ --rrd-cgi /var/www/sensord \ > /usr/lib/cgi-bin/sensord.cgi chmod a+rx /usr/lib/cgi-bin/sensord.cgi
Here, we create a CGI script that will display sensor readings from the database. You must specify the location of the round-robin database, the location of the directory where the images should be stored, and whether you want the load average displayed. The --rrd-cgi command-line parameter causes sensord(8) to display a suitable CGI script on stdout and then to exit. You will need to write this script to the CGI bin directory of your Web server, and edit the script if the image directory you chose is not the `/sensord/' directory of your Web server.
Finally, you should be able to view your sensor readings from the URL `http://localhost/cgi-bin/sensord.cgi'.
For example, a `sensord' initialization script might contain (among others) the following commands:
# Sample init.d scriptlet
echo -n "Loading AMD756 module: "
modprobe i2c-amd756 || { echo Fail. ; exit 1 ; }
echo OK.
echo -n "Loading W83781D module: "
modprobe w83781d || { echo Fail. ; exit 1 ; }
echo OK.
echo -n "Starting sensord: "
daemon sensord
Ignore the platform-specific shell functions; the general idea should be fairly clear.