lkml.org 
[lkml]   [2014]   [Nov]   [19]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
/
Date
From
SubjectRe: frequent lockups in 3.18rc4
On Wed, Nov 19, 2014 at 10:03:33AM -0500, Vivek Goyal wrote:

> Not being able to capture the dump I can understand but having wedged
> the machine so that it does not reboot after dump failure sounds bad.
> So you could not get machine to boot even after a power cycle? Would
> you remember what was failing. I am curious to know what did kdump do
> to make machine unbootable.

Power cycling was fine, because then it booted into the non-kdump kernel.
The issue was when I caused that kernel to panic, it would just sit there
wedged, with no indication it even tried to switch to the kdump kernel.

> > > Unless there's some magic step missing from the documentation at
> > > http://fedoraproject.org/wiki/How_to_use_kdump_to_debug_kernel_crashes
> > > then I'm not optimistic it'll be useful.
>
> I had a quick look at it and it basically looks fine. In fedora ideally
> it is just two steps process.
>
> - Reserve memory using crashkernel. Say crashkernel=160M
> - systemctl start kdump
> - Crash the system or wait for it to crash.
>
> So despite your bad experience in the past, I would encourage you to
> give it a try.

'the past' here, is two weeks ago, on Fedora 21.

But, since then, I've reinstalled that box with Fedora 20 because I didn't
trust gcc 4.9, and on f20 things are actually even worse.

Right now it doesn't even create the image correctly:

dracut: *** Stripping files done ***
dracut: *** Store current command line parameters ***
dracut: *** Creating image file ***
dracut: *** Creating image file done ***
kdumpctl: cat: write error: Broken pipe
kdumpctl: kexec: failed to load kdump kernel
kdumpctl: Starting kdump: [FAILED]

It works if I run a Fedora kernel, but not with a self-built one.
And there's zero information as to what I'm doing wrong.

I saw something similar on F21, got past it somehow a few weeks ago,
but I can't remember what I had to do. Unfortunatly that was still
fruitless as it didn't actually dump anything, leading to my frustration
with the state of kdump.

I'll try again when I put F21 back on that machine, but I'm
not particularly optimistic tbh.

Dave



\
 
 \ /
  Last update: 2014-11-19 17:01    [W:0.262 / U:0.136 seconds]
©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site