On Sun, 2014-05-25 at 05:12 -0400, Robert P. J. Day wrote:
On Sun, 25 May 2014, Robert P. J. Day wrote:
>
> (while this is probably not technically a fedora rawhide issue,
> since i'm trying this on rawhide, i figure this would be the best
> place to ask about it.)
>
> i really should know how to do this, but i'm confused about what
> happens when i try to configure which "kernel" messages i generate
> actually go to the console.
>
> on my rawhide system, my current log level settings are:
>
> # cat /proc/sys/kernel/printk
> 8 4 1 7
> #
>
> for which my long-time understanding is that the first value
> represents the value less than which messages of that loglevel will
> appear on the system console -- and a value of 8 means all of them.
>
> so having earlier set that first value manually with:
>
> # echo 8 > /proc/sys/kernel/printk
>
> i can now experiment by generating messages in userspace with
> variations like:
>
> # echo "<0> level 0" > /dev/kmsg
> # echo "<1> level 1" > /dev/kmsg
> # echo "<7> level 7" > /dev/kmsg
>
> and so on. now if i follow the contents of dmesg in real time with:
>
> $ dmesg -w
>
> i can indeed see all of these messages adding their brief contents to
> the dmesg buffer as i generate them.
>
> *however*, only messages with log level 0 are immediately dumped to
> all of the open xterm windows in my graphical session, which i equate
> with the system console. any messages with log levels 1 through 7 do
> *not* show up that way.
never mind, i think i can see what's happening ... what gets printed
to the console is controlled by rsyslog which is loading the "imklog"
module, which i'm going to assume is what i would configure to change
what log level messages go to the console, yes? so i guess i better do
some reading up on rsyslog and, in particular, that module.
does that sound about right?
well, in a typical modern Fedora config, journald gets its shot before
rsyslog, so it could also be interfering. check that out too.
--
Adam Williamson
Fedora QA Community Monkey
IRC: adamw | Twitter: AdamW_Fedora | XMPP: adamw AT happyassassin . net
http://www.happyassassin.net