> and if you have many non-dmesg commands reported on console, they can

I am not sure what this means. But it could be useful to also log to a
file all the output from /etc/rc startups.

> fill up what is displayed when you type dmesg.

Look at /var/run/dmesg.boot. (And see /etc/rc.d/dmesg.)

   Jeremy C. Reed
   http://bsd.reedmedia.net/