How to take a crash dump

How to take a crash dump

[SATHISH.J]

Hi,

I have "lcrash" installed on my system. I have 2.4.8 kernel. I would like
to know how to make a linux system panic so that I can take a crash dump
and analyse using "lcrash". Is there any command to make the system panis
as we have on other unices(SVR4 and unixware)?

Thanks in advance,


Warm regards,
Sathish.J
Systems Engineer
Tata Infotech Limited
80 Feet Road
Indra Nagar
Bangalore-560 038.

Re: How to take a crash dump

[Simon Turvey]

> I have "lcrash" installed on my system. I have 2.4.8 kernel. I would like
> to know how to make a linux system panic so that I can take a crash dump
> and analyse using "lcrash". Is there any command to make the system panis
> as we have on other unices(SVR4 and unixware)?

Try dereferencing a null pointer.  Works for me, intentionally or otherwise
:)

All the best,
    Simon

----- Original Message -----
From: "SATHISH.J" <sathish.j@tatainfotech.com>
To: "kernelnewbies" <kernelnewbies@nl.linux.org>; "linux-kernel"
<linux-kernel@vger.kernel.org>; "linux india programming"
<linux-india-programmers@lists.sourceforge.net>
Sent: Friday, January 04, 2002 9:00 AM
Subject: How to take a crash dump


> Hi,
>
> I have "lcrash" installed on my system. I have 2.4.8 kernel. I would like
> to know how to make a linux system panic so that I can take a crash dump
> and analyse using "lcrash". Is there any command to make the system panis
> as we have on other unices(SVR4 and unixware)?
>
> Thanks in advance,
>
>
> Warm regards,
> Sathish.J
> Systems Engineer
> Tata Infotech Limited
> 80 Feet Road
> Indra Nagar
> Bangalore-560 038.
>
> -
> To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
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> More majordomo info at  http://vger.kernel.org/majordomo-info.html
> Please read the FAQ at  http://www.tux.org/lkml/
>

Re: How to take a crash dump

[Patrick O'Rourke]

Simon Turvey wrote:

>>I have "lcrash" installed on my system. I have 2.4.8 kernel. I would like

>>to know how to make a linux system panic so that I can take a crash dump
>>and analyse using "lcrash". Is there any command to make the system panis
>>as we have on other unices(SVR4 and unixware)?


You can use Mission Critical Linux's crash dump analyser (aka crash) on
a live system and force it to panic via the "sys -panic" command.

The lkcd patch also adds an "alt-sysrq c" command that will force a dump.

Pat

-- 
Patrick O'Rourke
porourke@egenera.com

Re: How to take a crash dump

[Erik Mouw]

On Fri, Jan 04, 2002 at 02:30:20PM +0530, SATHISH.J wrote:
> I have "lcrash" installed on my system. I have 2.4.8 kernel. I would like
> to know how to make a linux system panic so that I can take a crash dump
> and analyse using "lcrash". Is there any command to make the system panis
> as we have on other unices(SVR4 and unixware)?

I wrote a toy module that does exactly what you want:

  http://www.lart.tudelft.nl/lartware/port/lart.c

I still have to get the module into Linus' tree so Christoph Hellwig
will drive to .nl to buy me a beer :)


Erik

-- 
J.A.K. (Erik) Mouw, Information and Communication Theory Group, Faculty
of Information Technology and Systems, Delft University of Technology,
PO BOX 5031, 2600 GA Delft, The Netherlands  Phone: +31-15-2783635
Fax: +31-15-2781843  Email: J.A.K.Mouw@its.tudelft.nl
WWW: http://www-ict.its.tudelft.nl/~erik/

Re: How to take a crash dump

[Suparna Bhattacharya]

Erik Mouw wrote:
> 
> On Fri, Jan 04, 2002 at 02:30:20PM +0530, SATHISH.J wrote:
> > I have "lcrash" installed on my system. I have 2.4.8 kernel. I would like
> > to know how to make a linux system panic so that I can take a crash dump
> > and analyse using "lcrash". Is there any command to make the system panis
> > as we have on other unices(SVR4 and unixware)?
> 

Have you tried using the Alt+Sysrq+c key combination ? 

We had checked in some changes to enable non-disruptive dumps to be
taken this way as 
well (i.e. you can get a dump without having to reboot the system) but
that piece is going to be in lkcd 4.01. 

BTW, you can also trigger a crash dump conditionally using dprobes.

Regards
Suparna

> I wrote a toy module that does exactly what you want:
> 
>   http://www.lart.tudelft.nl/lartware/port/lart.c
> 
> I still have to get the module into Linus' tree so Christoph Hellwig
> will drive to .nl to buy me a beer :)
> 
> Erik
> 
> --
> J.A.K. (Erik) Mouw, Information and Communication Theory Group, Faculty
> of Information Technology and Systems, Delft University of Technology,
> PO BOX 5031, 2600 GA Delft, The Netherlands  Phone: +31-15-2783635
> Fax: +31-15-2781843  Email: J.A.K.Mouw@its.tudelft.nl
> WWW: http://www-ict.its.tudelft.nl/~erik/
> -
> To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
> the body of a message to majordomo@vger.kernel.org
> More majordomo info at  http://vger.kernel.org/majordomo-info.html
> Please read the FAQ at  http://www.tux.org/lkml/