Re: kexec/kdump of a kvm guest?

Avi Kivity
2008-07-05T11:20:14Z

Mike Snitzer wrote:
> My host is x86_64 RHEL5U1 running 2.6.25.4 with kvm-70 (kvm-intel).
>
> When I configure kdump in the guest (running 2.6.22.19) and force a
> crash (with 'echo c > /proc/sysrq-trigger) kexec boots the kdump
> kernel but then the kernel hangs (before it gets to /sbin/init et al).
> On the host, the associated qemu is consuming 100% cpu.
>
> I really need to be able to collect vmcores from my kvm guests. So
> far I can't (on raw hardware all works fine).
>
>

I've tested this a while ago and it worked (though I tested regular
kexecs, not crashes); this may be a regression.

Please run kvm_stat to see what's happening at the time of the crash.

--
I have a truly marvellous patch that fixes the bug which this
signature is too narrow to contain.