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

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.