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

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Message-ID: <20160825081049.GA4235@dhcp22.suse.cz>
Date:   Thu, 25 Aug 2016 10:10:49 +0200
From:   Michal Hocko <mhocko@...nel.org>
To:     Himanshu Madhani <himanshu.madhani@...gic.com>
Cc:     linux-kernel <linux-kernel@...r.kernel.org>,
        Dave Young <dyoung@...hat.com>, Baoquan He <bhe@...hat.com>,
        Vivek Goyal <vgoyal@...hat.com>, kexec@...ts.infradead.org
Subject: Re: Capturing crash with 4.6.0 and above kernel does not work

[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 “crashkenrel” 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?

> 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