2018-01-16 13:41 GMT+01:00 Josh Boyer <jwboyer@fedoraproject.org>:
On Tue, Jan 9, 2018 at 1:51 PM, Maxim Burgerhout <maxim@wzzrd.com> wrote:
> I'm getting kernel panics in a VM that functions as a hypervisor, the moment
> I spin up the nested guest (on AMD ThreadRipper / Fedora 27). That is
> annoying, of course, so I try to be a good citizen and file a bug.
>
> For some reason though, I cannot get the core dumped. I get a core fine with
> sysrq, but not with this actual panic. I've followed [1] to set up kdump and
> crash, but everytime I trigger the crash and see my VM reboot, I see an
> empty /var/crash afterwards.
>
> As was able to get the vmcore written to /var/crash on in a RHEL7 guest, I'm
> starting to suspect a bug, but I'm unsure.
>
> Any pointers on how to debug this?
>
> [1] https://fedoraproject.org/wiki/How_to_use_kdump_to_debug_kernel_crashes

Adding the Fedora kernel list.

Kdump isn't automatically tested in Fedora and while it can work, it
can often be broken as well.  There might be someone on the kernel
list that is more familiar with the current state of kdump support in
Fedora, or alternative methods for getting the kernel backtrace.

​​I'm also interested in this, because I have a reproducible system crash but I can't ​capture the vmcore, the crash kernel only writes the dmesg.​