FAQ Search Today's Posts Mark Forums Read
» Video Reviews

» Linux Archive

Linux-archive is a website aiming to archive linux email lists and to make them easily accessible for linux users/developers.


» Sponsor

» Partners

» Sponsor

Go Back   Linux Archive > Redhat > Crash Utility

 
 
LinkBack Thread Tools
 
Old 02-04-2011, 08:08 PM
nishant mungse
 
Default How to work with crash utility.

Hello all,
I am new to this crash utility and have installed crash-5.1.1 on fedora11. Actually i searched a lot on net but i am unable to understand that. I tried many thing but it failed.
I have written a module and it is giving oops after mke2fs and wann to use crash utility to solve this problem.* Will anyone guide from basic steps how to use crash. Please help me out.



Regards,
Nishant.

--
Crash-utility mailing list
Crash-utility@redhat.com
https://www.redhat.com/mailman/listinfo/crash-utility
 
Old 02-04-2011, 09:09 PM
Ratnam Tatavarty
 
Default How to work with crash utility.

Hi Nishant,*Welcome to the group! Your usecase for using Crash is very apt and you can look for the following steps to start with:
- Did you configure Kdump utility?**In case you did not: Kdump utility lets you take a core-dump of the whole kernel once it hits a panic/oops situation, and save the same in a specified location. It is available as part of kexec-tools package.
- You may want to try a dry run by inducing a panic with echo 'c' > */proc/sysrq-trigger and checking if kdump captured a dump file in the directory specified in the /etc/kdump.conf or not.- Once the above two basic steps are done, you are now set to analyze your problem with the captured context in the coredump file using Crash.
- Install the kernel-debuginfo packages for the exact version of kernel you are trying to debug.*You can find the debuginfo packages in a yum/fedora public repos.- Now start Crash with the two important parameters: coredump file (called as namelist file) location and place where you kernel-debuginfo file (vmlinux). You can find the later*/usr/lib/debug/lib/modules/2.6.29.4-167.fc11.x86_64/vmlinux (note that the exact kernel version might be different)

Now the command to use is: crash <path to the vmlinux file> <path to your coredump file>
Hope this helps in getting you started.*
Regards,*

Ratnam

On Fri, Feb 4, 2011 at 1:08 PM, nishant mungse <nishantmungse@gmail.com> wrote:

Hello all,
I am new to this crash utility and have installed crash-5.1.1 on fedora11. Actually i searched a lot on net but i am unable to understand that. I tried many thing but it failed.
I have written a module and it is giving oops after mke2fs and wann to use crash utility to solve this problem.* Will anyone guide from basic steps how to use crash. Please help me out.




Regards,
Nishant.


--

Crash-utility mailing list

Crash-utility@redhat.com

https://www.redhat.com/mailman/listinfo/crash-utility




--
Crash-utility mailing list
Crash-utility@redhat.com
https://www.redhat.com/mailman/listinfo/crash-utility
 
Old 02-04-2011, 09:11 PM
Dave Anderson
 
Default How to work with crash utility.

----- Original Message -----
> Hello all,
> I am new to this crash utility and have installed crash-5.1.1 on
> fedora11. Actually i searched a lot on net but i am unable to
> understand that. I tried many thing but it failed.

You're not exactly clear what has "failed" ...

> I have written a module and it is giving oops after mke2fs and wann to
> use crash utility to solve this problem. Will anyone guide from basic
> steps how to use crash. Please help me out.

Ok, but I don't know whether you've already got a dumpfile, and you're asking
how to do get one, or if you've got one but have questions about how to
use the crash utility with it, or what?

Nonetheless...

If you've never used any crash utility before, then I'd
suggest looking at the white paper here:

http://people.redhat.com/anderson/crash_whitepaper

But in a nutshell, first you will need to get the kernel-debuginfo
and kernel-debuginfo-common packages for the F11 installation
that you are running. If for example, you are running say, version
2.6.30.9-96.fc11 on an x86_64 machine, then the packages can be
found here:

http://koji.fedoraproject.org/koji/buildinfo?buildID=139687

And from that page you would download:

kernel-debuginfo-2.6.30.9-96.fc11.x86_64.rpm
kernel-debuginfo-common-x86_64-2.6.30.9-96.fc11.x86_64.rpm

It's highly unlikely you're actually running 2.6.30.9-96.fc11, so go
here to find your specific kernel version's files:

http://koji.fedoraproject.org/koji/packageinfo?packageID=8

To get a kernel as old as F11, you'll have to use the drop-down
box on the right side of the page, and try to find yours.

When you find them, install both packages with with "rpm -ivh".

After doing that, the vmlinux file that you need to work with the
crash utility would be located here:

/usr/lib/debug/lib/modules/<kernel-version>/vmlinux

You could also find it quickly by just entering "crash":

$ crash

and the invocation header will show the fully qualified pathname
next to "KERNEL:".

And so you would invoke the crash utility on your dumpfile like this:

$ crash <path-to>/vmlinux <path-to>/vmcore

Now, if you don't have kdump set up, then that's a whole other issue...

There should be a cheat sheet somewhere to tell how to do it, but
it's basically this:

$ chkconfig kdump on

Modify the running kernel's command line in /boot/grub/grub.conf to
carve out memory space for the kdump kernel by adding "crashkernel=#M@#M"
to the end of the line, like this:

kernel /vmlinuz-2.6.30.9-96.fcll.x86_64 ...[cut ]... crashkernel=128M@32M

Then reboot. When the system comes up again, enter:

$ service kdump status

and hopefully it's up and running.

The crash the system -- kdump should save the dumpfile in a subdirectory of
the /var/crash directory, with the name "vmcore". Then run crash as shown
above:

$ crash /usr/lib/debug/lib/modules/2.6.30.9-96.fc11.x86_64/vmlinux <path-to>/vmcore

To be able to fully debug module-related crashes, you should run
the "mod -S" command first to load the debuginfo data of all modules,
and then enter "bt", which will give you a backtrace of the crashing task.

That should hopefully get you started...

Dave

--
Crash-utility mailing list
Crash-utility@redhat.com
https://www.redhat.com/mailman/listinfo/crash-utility
 
Old 02-11-2011, 10:58 AM
nishant mungse
 
Default How to work with crash utility.

On Sat, Feb 5, 2011 at 2:38 AM, nishant mungse <nishantmungse@gmail.com> wrote:

Hello all,
I am new to this crash utility and have installed crash-5.1.1 on fedora11. Actually i searched a lot on net but i am unable to understand that. I tried many thing but it failed.
I have written a module and it is giving oops after mke2fs and wann to use crash utility to solve this problem.* Will anyone guide from basic steps how to use crash. Please help me out.




Regards,
Nishant.
Hello all,
I tried this command.*[root@localhost crash-5.1.2]# crash /usr/lib/debug/lib/modules/2.6.30.9-96.fc11.i586/vmlinux /var/crash/2011-02-11-16:32/vmcore

The Result is:

GNU gdb (GDB) 7.0Copyright (C) 2009 Free Software Foundation, Inc.License GPLv3+: GNU GPL version 3 or later <http://gnu.org/licenses/gpl.html>
This is free software: you are free to change and redistribute it.There is NO WARRANTY, to the extent permitted by law. *Type "show copying"and "show warranty" for details.
This GDB was configured as "i686-pc-linux-gnu"...
crash: invalid kernel virtual address: 66c67d8b *type: "possible"WARNING: cannot read cpu_possible_map
crash: invalid kernel virtual address: 518bc845 *type: "present"WARNING: cannot read cpu_present_mapcrash: invalid kernel virtual address: 8b127b33 *type: "online"WARNING: cannot read cpu_online_map
crash: /usr/lib/debug/lib/modules/2.6.30.9-96.fc11.i586/vmlinux and /var/crash/2011-02-11-16:32/vmcore do not match!
Usage:**crash [-h [opt]][-v][-s][-i file][-d num] [-S] [mapfile] [namelist] [dumpfile]

Enter "crash -h" for details.

I am currently using kernel version 2.6.35.5, fedora11.*
Hoping for some help.....

Regards*Nishant
--
Crash-utility mailing list
Crash-utility@redhat.com
https://www.redhat.com/mailman/listinfo/crash-utility
 
Old 02-11-2011, 12:37 PM
Dave Anderson
 
Default How to work with crash utility.

----- Original Message -----

>
> I tried this command.
> [root@localhost crash-5.1.2]# crash
> /usr/lib/debug/lib/modules/2.6.30.9-96.fc11.i586/vmlinux /var/crash/2011-02-11-16:32/vmcore
>
> The Result is:
>
> GNU gdb (GDB) 7.0
> Copyright (C) 2009 Free Software Foundation, Inc.
> License GPLv3+: GNU GPL version 3 or later <
> http://gnu.org/licenses/gpl.html >
> This is free software: you are free to change and redistribute it.
> There is NO WARRANTY, to the extent permitted by law. Type "show copying"
> and "show warranty" for details.
> This GDB was configured as "i686-pc-linux-gnu"...
>
>
> crash: invalid kernel virtual address: 66c67d8b type: "possible"
> WARNING: cannot read cpu_possible_map
> crash: invalid kernel virtual address: 518bc845 type: "present"
> WARNING: cannot read cpu_present_map
> crash: invalid kernel virtual address: 8b127b33 type: "online"
> WARNING: cannot read cpu_online_map
> crash: /usr/lib/debug/lib/modules/2.6.30.9-96.fc11.i586/vmlinux and
> /var/crash/2011-02-11-16:32/vmcore do not match!
>
> Usage:
> crash [-h [opt]][-v][-s][-i file][-d num] [-S] [mapfile] [namelist] [dumpfile]
>
> Enter "crash -h" for details.
>
>
> I am currently using kernel version 2.6.35.5, fedora11.

If the vmcore file was generated from the 2.6.35.5 kernel, then you are
using the wrong vmlinux file -- you need to find the kernel-debuginfo
packages for the 2.6.30.9-96.fc11.i586 kernel.

Dave


--
Crash-utility mailing list
Crash-utility@redhat.com
https://www.redhat.com/mailman/listinfo/crash-utility
 
Old 02-11-2011, 12:42 PM
Dave Anderson
 
Default How to work with crash utility.

----- Original Message -----
> >
> > I am currently using kernel version 2.6.35.5, fedora11.
>
> If the vmcore file was generated from the 2.6.35.5 kernel, then you are
> using the wrong vmlinux file -- you need to find the kernel-debuginfo
> packages for the 2.6.30.9-96.fc11.i586 kernel.
^^^^^^^^^^^^^^^^^^^^^

Sorry -- you need the kernel-debuginfo packages for 2.6.35.5 kernel.

Dave

--
Crash-utility mailing list
Crash-utility@redhat.com
https://www.redhat.com/mailman/listinfo/crash-utility
 

Thread Tools




All times are GMT. The time now is 12:17 PM.

VBulletin, Copyright ©2000 - 2014, Jelsoft Enterprises Ltd.
Content Relevant URLs by vBSEO ©2007, Crawlability, Inc.
Copyright 2007 - 2008, www.linux-archive.org