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* Re: [patch] netconsole - log kernel messages over the network. 2.4.10.
@ 2001-09-27 15:18 Ookhoi
  2001-09-27 18:05 ` Andrew Morton
  0 siblings, 1 reply; 13+ messages in thread
From: Ookhoi @ 2001-09-27 15:18 UTC (permalink / raw)
  To: linux-kernel

Hi All,

Ingo was not aware of the sourceforge project, and suggested me to
resend my reply to lkml. Does the patch work for you guys? Do I do
something wrong? That would be more than possible. :-)


----- Forwarded message from Ookhoi <ookhoi@dds.nl> -----

To: Ingo Molnar <mingo@elte.hu>
Cc: netconsole-devel@lists.sourceforge.net

Hi Ingo,

> this is the first public release of the 'netconsole patch', a debugging
> patch that implements kernel-level network logging via UDP packets.

Is this different from the netconsole project on sourceforge? The last
message on that lists seemes to be from july, and you didn't cc it. 

> the kernel patch (against 2.4.10 or 2.4.9-ac), and a simple user-space
> tool to display netconsole messages can be found at:
>
> 	http://redhat.com/~mingo/netconsole-patches/

Can you also make older patches available for testing? The current
netconsole-2.4.10-B1 doesn't seem to work for me on plain 2.4.10 or
2.4.9-ac15 patched with Rik his latest vm patch. The patch applies fine,
but I can't load the module:

cuddle:~# uname -a
Linux cuddle 2.4.9-ac15 #1 Thu Sep 27 13:54:51 CEST 2001 i686 unknown
cuddle:~# insmod netconsole dev=eth0 target_ip=0x0a604875 source_port=6666 target_port=5555
Using /lib/modules/2.4.9-ac15/kernel/drivers/net/netconsole.o
/lib/modules/2.4.9-ac15/kernel/drivers/net/netconsole.o: init_module: Operation not permitted
Hint: insmod errors can be caused by incorrect module parameters, including invalid IO or IRQ parameters

The same message for plain 2.4.10, and the same when I use the script
netconsole-server included in netconsole-client-20010927. I also tried
it with the target_eth_byte0 thingies, with the mac address from the
local nic.

Target ip address is 10.96.72.117 (I hope 0x0a604875 is oke)

> sample startup of the netconsole on the server:
> 
>      insmod netconsole dev=eth1 target_ip=0x0a000701 \
>                   source_port=6666 \
>                   target_port=6666 \
>                   target_eth_byte0=0x00 \
>                   target_eth_byte1=0x90\
>                   target_eth_byte2=0x27 \
>                   target_eth_byte3=0x8C \
>                   target_eth_byte4=0xA0 \
>                   target_eth_byte5=0xA8
> 
> and on the client:
> 
> 	# ./netconsole-client -server 10.0.7.5 -client 10.0.7.1 -port 6666
>         [...network console startup...]
>         netconsole: network logging started up successfully!
>         SysRq : Loglevel set to 9
> 
> more about features and limitations can be found under:
> 
> 	Documentation/networking/netlogging.txt
> 
> reports, comments, suggestions welcome.

Somebody more or less asked this already, but, will things like SysRq
work in the future? That would be great. :-)  Thnx!

	Ookhoi

----- End forwarded message -----

^ permalink raw reply	[flat|nested] 13+ messages in thread
* [patch] netconsole - log kernel messages over the network. 2.4.10.
@ 2001-09-26 20:04 Ingo Molnar
  2001-09-26 19:36 ` Marcelo Tosatti
  0 siblings, 1 reply; 13+ messages in thread
From: Ingo Molnar @ 2001-09-26 20:04 UTC (permalink / raw)
  To: linux-kernel; +Cc: linux-net, netdev


this is the first public release of the 'netconsole patch', a debugging
patch that implements kernel-level network logging via UDP packets.

the special thing about this approach is the ability to send 'emergency'
network packets even from IRQ handlers. This enables the netconsole to
send enough info even if we crash in init or in an interrupt handler.

another property of netconsole is that it's able to share the networking
device with other kernel subsystems, like the TCP/IP stack. So the
networking device is not dedicated for netconsole use, it's transparently
shared.

netconsole is also designed to be robust, it goes straight to the network
driver, so it does not depend on the networking stack to log messages.

kernel-level netlogging is useful in a number of scenarios:

 - if remotely managed systems with no serial cable logging keep crashing
   without any trace of an oops message in the userspace log. (the patch
   was written to debug such a crash. Original idea of sending an
   emergency packet from IRQ handlers comes from Daniel Veillard who's
   system produced the crash - thanks Daniel!)

 - if for whatever reason the amount of logging is so high that a serial
   console cannot hold it and disks can not keep up - or in cases where
   logged messages disturb the debugged subsystem. I'm sure fellow VM
   hackers will find this useful :-)

 - the netconsole can be used to emit crashdumps over the network, without
   any delay between the point of crash and start of netlogging.

the kernel patch (against 2.4.10 or 2.4.9-ac), and a simple user-space
tool to display netconsole messages can be found at:

	http://redhat.com/~mingo/netconsole-patches/

sample startup of the netconsole on the server:

     insmod netconsole dev=eth1 target_ip=0x0a000701 \
                  source_port=6666 \
                  target_port=6666 \
                  target_eth_byte0=0x00 \
                  target_eth_byte1=0x90\
                  target_eth_byte2=0x27 \
                  target_eth_byte3=0x8C \
                  target_eth_byte4=0xA0 \
                  target_eth_byte5=0xA8

and on the client:

	# ./netconsole-client -server 10.0.7.5 -client 10.0.7.1 -port 6666
        [...network console startup...]
        netconsole: network logging started up successfully!
        SysRq : Loglevel set to 9

more about features and limitations can be found under:

	Documentation/networking/netlogging.txt

reports, comments, suggestions welcome.

	Ingo


^ permalink raw reply	[flat|nested] 13+ messages in thread

end of thread, other threads:[~2002-03-09 17:11 UTC | newest]

Thread overview: 13+ messages (download: mbox.gz follow: Atom feed
-- links below jump to the message on this page --
2001-09-27 15:18 [patch] netconsole - log kernel messages over the network. 2.4.10 Ookhoi
2001-09-27 18:05 ` Andrew Morton
2001-09-27 18:30   ` Ookhoi
2001-09-28  2:53   ` Albert Cranford
2001-09-28  7:45     ` [patch] netconsole-2.4.10-C2 Ingo Molnar
2002-03-09 17:17       ` netconsole patch for 2.5? Barton, Christopher
  -- strict thread matches above, loose matches on Subject: below --
2001-09-26 20:04 [patch] netconsole - log kernel messages over the network. 2.4.10 Ingo Molnar
2001-09-26 19:36 ` Marcelo Tosatti
2001-09-26 21:15   ` jamal
2001-09-27  5:45     ` Ingo Molnar
2001-09-26 21:29   ` Andreas Dilger
2001-09-26 23:46     ` Andreas Dilger
2001-09-27  5:28       ` Ingo Molnar

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