[libvirt] Cannot dump core: error: Requested operation is not valid: domain is marked for auto destroy

[Jiri Denemark]

On Thu, Oct 08, 2015 at 12:08:58 +0100, Daniel P. Berrange wrote:
> On Thu, Oct 08, 2015 at 12:06:09PM +0100, Richard W.M. Jones wrote:
> > 
> > I wonder if there's a reason why it is not possible to dump the core
> > of a KVM domain which is set to autodestroy.
> > 
> > $ virsh dump guestfs-4xe592eyqq4rfnk9 /tmp/guestfs-4xe592eyqq4rfnk9.core
> > error: Failed to core dump domain guestfs-4xe592eyqq4rfnk9 to /tmp/guestfs-4xe592eyqq4rfnk9.core
> > error: Requested operation is not valid: domain is marked for auto destroy
> > 
> > All libguestfs domains have the autodestroy flag, but I am trying to
> > debug one which is crashing in the guest (RHBZ#1269779) and having the
> > ability to dump it would be very helpful.
> > 
> > I added the following patch to libvirt, which allowed me to dump the
> > domain with no apparent ill effects.
> 
> Yep, I see no reason to block use of the core dump API. Looking at the
> patch I think this is probably just an over-sight - ie it is merely
> blocked as an accidental side-effect of us blocking migration.

I think you should actually use virsh dump --memory-only ... to go
through dump-guest-memory instead of migration. This should create an
elf formated core which crash supports better and even on ppc64, for
example.

Jirka