25.8. Debugging Rsyslog

To run rsyslogd in debugging mode, use the following command:

rsyslogd -dn

rsyslogd -dn

With this command, rsyslogd produces debugging information and prints it to the standard output. The -n stands for "no fork". You can modify debugging with environmental variables, for example, you can store the debug output in a log file. Before starting rsyslogd, type the following on the command line:

export RSYSLOG_DEBUGLOG="path"
export RSYSLOG_DEBUG="Debug"

export RSYSLOG_DEBUGLOG="path"
export RSYSLOG_DEBUG="Debug"

Replace path with a desired location for the file where the debugging information will be logged. For a complete list of options available for the RSYSLOG_DEBUG variable, see the related section in the rsyslogd(8) manual page.

To check if syntax used in the /etc/rsyslog.conf file is valid use:

rsyslogd -N 1

rsyslogd -N 1

Where 1 represents level of verbosity of the output message. This is a forward compatibility option because currently, only one level is provided. However, you must add this argument to run the validation.