[arch-general] Kernel code dump retrieval

[Anatol Pomozov]

Hi

On Thu, Oct 16, 2014 at 4:57 AM, Leonidas Spyropoulos
<artafinde at gmail.com> wrote:
> Hello list,
>
> I'm experiencing an issue while compiling big projects (i.e. linux
> kernel but not limited to that). The issue seems to be related to
> CPUFREQ and I'm trying to track it down.
>
> While compiling the linux-ck kernel the kernel panics and produce a core
> dumps.

When you say "produce a core dumps" what exactly you see. How do you
know it produces the kernel dump?

> I'm trying to get the core dump but I'm not able to access it after
> hard reset. I tried enabling journalctl Storage=Auto to write to disk without
> luck.

After the crash happens kernel cannot write anything to disk nor send
via network. Dealing with disk/network/... requires valid kernel data
structures and you don't have them anymore.

Once kernel crashed it has only one option - reboot.

>
> My FS is btrfs and the CPU is AMD FX-8120. The CPU is not overclocked
> [1] and the Cool And Quiet is enabled alond with other power saving
> options in BIOS (like C6 State).
>
> How can I access the kernel core dump after crash?

Check kdump https://wiki.archlinux.org/index.php/Kdump - it is
probably what you are looking for.