Re: Capturing crash with 4.6.0 and above kernel does not work

[Himanshu Madhani]

On 8/25/16, 1:10 AM, "Michal Hocko" <mhocko@xxxxxxxxxx> wrote:

>[Let's add kdump people]
>
>On Wed 24-08-16 16:38:56, Himanshu Madhani wrote:
>> Hello list,
>> 
>> I am wondering if anybody has issue capturing crash dump with the 4.6.0 and above kenrel.
>> 
>> I have a system, when booted in 4.5.7 kernel is able to capture crash dump.
>> However, when I boot this system in 4.6.4 and 4.7.2 kernel, crash dump is not 
>> able to capture any crash. 
>> 
>> I am still facing same issue with 4.8.0-rc2+ kernel and from the error at the command prompt, 
>> it seems like kexec is ignoring âcrashkenrelâ parameter. 
>> 
>> I added below information in https://bugzilla.kernel.org/show_bug.cgi?id=119291. 
>> 
>> # uname -r
>> 4.8.0-rc2+
>> 
>> # cat /proc/cmdline 
>> ro root=/dev/mapper/vg_dut4110-lv_root rd_NO_LUKS  KEYBOARDTYPE=pc KEYTABLE=us LANG=en_US.UTF-8 rd_NO_MD SYSFONT=latarcyrheb-sun16 crashkernel=512M rd_LVM_LV=vg_dut4110/lv_swap rd_LVM_LV=vg_dut4110/lv_root rd_NO_DM rhgb quiet
>> 
>> # service kdump status
>> Kdump is not operational
>> 
>> # service kdump start
>> Memory for crashkernel is not reserved
>> Please reserve memory by passing "crashkernel=X@Y" parameter to the kernel
>> Starting kdump:                                            [FAILED]
>
>It smells like the crash kernel reservation has failed. Could you
>provide the full kernel log?

Attached is kernel log from fresh kernel compile of 4.6.5 (linux-stable) tree

root@dut4062:~# cat /proc/cmdline 
ro root=/dev/mapper/VolGroup-lv_root rd_NO_LUKS LANG=en_US.UTF-8 rd_NO_MD rd_LVM_LV=VolGroup/lv_swap SYSFONT=latarcyrheb-sun16 crashkernel=512M rd_LVM_LV=VolGroup/lv_root  KEYBOARDTYPE=pc KEYTABLE=us rd_NO_DM rhgb console=ttyS0 console=ttyS0,115200n8

root@dut4062:~# service kdump status

Kdump is not operational

root@dut4062:~# service kdump start
Memory for crashkernel is not reserved
Please reserve memory by passing "crashkernel=X@Y" parameter to the kernel
Starting kdump:                                            [FAILED]
root@dut4062:~# 

Messages in log fil

Aug 25 10:42:16 dut4062 kdump: kexec: failed to load kdump kernel
Aug 25 10:42:16 dut4062 kdump: failed to start up


root@dut4062:~# kexec --ver
kexec-tools 2.0.0 released 19th July 2008
root@dut4062:~# 

root@dut4062:~# crash --version

crash 7.1.5++
Copyright (C) 2002-2016  Red Hat, Inc.
Copyright (C) 2004, 2005, 2006, 2010  IBM Corporation
Copyright (C) 1999-2006  Hewlett-Packard Co
Copyright (C) 2005, 2006, 2011, 2012  Fujitsu Limited
Copyright (C) 2006, 2007  VA Linux Systems Japan K.K.
Copyright (C) 2005, 2011  NEC Corporation
Copyright (C) 1999, 2002, 2007  Silicon Graphics, Inc.
Copyright (C) 1999, 2000, 2001, 2002  Mission Critical Linux, Inc.
This program is free software, covered by the GNU General Public License,
and you are welcome to change it and/or distribute copies of it under
certain conditions.  Enter "help copying" to see the conditions.
This program has absolutely no warranty.  Enter "help warranty" for details.
 
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Copyright (C) 2013 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.
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Let me know if any other details are needed. I have multiple servers which exhibit same issues.






>
>> message file confirms that kexec was not able to start the service 
>> 
>> Aug 15 10:41:17 dut4110 kdump: kexec: failed to load kdump kernel
>> Aug 15 10:41:17 dut4110 kdump: failed to start up
>> 
>> Note, that same option is able to load kdump service for 4.5.7 kernel.  
>> 
>> I can provide any details needed to help resolve this issue. 
>> 
>> Thanks,
>> - Himanshu
>> 
>
>-- 
>Michal Hocko
>SUSE Labs

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