Redirecting syslogd Error Messages to an Error Log or to a Null File?

Question

I have an old PowerPC laptop (old Mac Powerbook G4) that I am running a variant of Debian Squeeze on (MintPPC 9).

I keep getting Kernel error messages when I am connected to a particular wireless network but not at other times. I suspect, but have not proven, that it is arising from the networking module. The error messages overwhelm anything I am doing at the time (e.g. overlaying a CLI Emacs display) but do not otherwise seem to influence the function of the machine, even the networking seems to soldier on.

Is there a way to redirect error messages from syslogd specifically to an error log or possibly /dev/null but to leave other error messages going to stdout. I know that 2>> will direct error messages but since I did not consciously start syslogd I don't know how to do so.

Sometimes the error messages are more elaborate but here is an example:

Message form syslogd@debian at Dec 10 09:48:02 ...
 kernel:[   720.749515] -----------[  cut here  ]---------------

Answer 1

What you're experiencing is a walled message.

Debian's default syslog daemon, rsyslog, will with the default configuration send messages with severity emerg from any facility (*) to all logged in users, via wall (from /etc/rsyslog.conf):

#
# Emergencies are sent to everybody logged in.
#
*.emerg                         :omusrmsg:*

You can change this by configuring Rsyslog to do something else.

For example (though I'm not sure if it's really advisable to make emergency messages ignorable) you could change the /var/log/messages catch-all rule (above the *.emerg)

*.=info;*.=notice;*.=warn;\
        auth,authpriv.none;\
        cron,daemon.none;\
        mail,news.none          -/var/log/messages

to also catch *.emerg and comment out the rule below.