Netconsole and logging everything from /dev/console

Netconsole and logging everything from /dev/console

[Martin Michlmayr]

I'm supporting a number of consumer devices (e.g. small NAS devices)
in Debian.  They typically don't export the serial console and don't
have any other output devices.  We perform the installation via SSH
on such devices and start SSH automatically when the system boots so
people can login.  This works pretty well but sometimes a device stops
to boot for no good reason.  This is usually really hard to debug
since we don't have any logs at all.

I could activate netconsole in order to see kernel messages but then I
still wouldn't see anything that's printed by the ramdisk and later
when services are started.  Ideally, I'd like to have an option for
netconsole to show every message that is also shown on the console.

Do you think that would be possible?
-- 
Martin Michlmayr
http://www.cyrius.com/

Re: Netconsole and logging everything from /dev/console

[Matt Mackall]

On Fri, Nov 16, 2007 at 06:43:15PM +0100, Martin Michlmayr wrote:
> I'm supporting a number of consumer devices (e.g. small NAS devices)
> in Debian.  They typically don't export the serial console and don't
> have any other output devices.  We perform the installation via SSH
> on such devices and start SSH automatically when the system boots so
> people can login.  This works pretty well but sometimes a device stops
> to boot for no good reason.  This is usually really hard to debug
> since we don't have any logs at all.
> 
> I could activate netconsole in order to see kernel messages but then I
> still wouldn't see anything that's printed by the ramdisk and later
> when services are started.  Ideally, I'd like to have an option for
> netconsole to show every message that is also shown on the console.
> 
> Do you think that would be possible?

It is, definitely, you just need to wire up a tty struct's write
method to netconsole's and add it to the console registration. But I
haven't had any time to work on this in a while.

-- 
Mathematics is the supreme nostalgia of our time.

Re: Netconsole and logging everything from /dev/console

[Martin Michlmayr]

* Matt Mackall <mpm@selenic.com> [2007-11-16 12:50]:
> > Do you think that would be possible?
> 
> It is, definitely, you just need to wire up a tty struct's write
> method to netconsole's and add it to the console registration. But I
> haven't had any time to work on this in a while.

Where would I look for examples I could follow?
-- 
Martin Michlmayr
http://www.cyrius.com/

Re: Netconsole and logging everything from /dev/console

[Ferenc Wagner]

On 2007-11-17 Martin Michlmayr wrote:

> * Matt Mackall <mpm <at> selenic.com> [2007-11-16 12:50]:
>
>>> Do you think that would be possible?
>> 
>> It is, definitely, you just need to wire up a tty struct's write
>> method to netconsole's and add it to the console registration. But I
>> haven't had any time to work on this in a while.
>
> Where would I look for examples I could follow?

Hi,

Such feature would indeed be useful.  Did you get anywhere with it?
-- 
Thanks,
Feri.

Re: Netconsole and logging everything from /dev/console

[Martin Michlmayr]

* Ferenc Wagner <wferi@niif.hu> [2008-10-30 15:39]:
> >> It is, definitely, you just need to wire up a tty struct's write
> >> method to netconsole's and add it to the console registration. But I
> >> haven't had any time to work on this in a while.
> >
> > Where would I look for examples I could follow?
> Such feature would indeed be useful.  Did you get anywhere with it?

Nope.
-- 
Martin Michlmayr
http://www.cyrius.com/