Re: [PATCH v2] netconsole: Add tty driver

[Struan Bartlett <struan.bartlett@gmail.com>]

On 02/04/2014 14:16, Tetsuo Handa wrote:
> Struan Bartlett wrote:
>> Adds tty driver to netconsole module. When module is loaded,
>> creates /dev/netcon0 device and enables support for console=netcon0
>> kernel cmdline option, causing /dev/console output to be sent to
>> /dev/netcon0. This allows startup/shutdown script output from
>> headless platforms to be logged over (secure) network.
> 
> Excuse me, but I think that the netconsole logging can work only during network
> interfaces (e.g. eth0) are up. Did this patch description assume that the
> network interfaces are up before the startup script is started and the shutdown
> script is finished before the network interfaces are down?

Yes it did. I hope I have clarified that in the v3 patch description.
In practice, at least in a Debian environment: i) the netconsole module itself
is generally capable of raising the network interface when it is loaded by the
initramfs init script (which precedes all /etc/init.d/* scripts); ii) very
little of consequence tends to happens during shutdown after networking is
stopped; iii) equally, it is not usually problematic to disable the networking
shutdown script, since it runs on platforms about to be rebooted or powered off.
We do this by editing the Default-Stop LSB header in /etc/init.d/networking.

> By the way, I uploaded a logger specialized for receiving netconsole messages
> to http://sourceforge.jp/projects/akari/scm/svn/tree/head/branches/udplogger/ .

Thank you. I'll check it out.