Okay, this is probably a race condition bug. If remove: <iothreads>1</iothreads> and iothread='1' from the disk which causes the command to change from:
-device virtio-blk- pci,iothread=iothread1,scsi=off,bus=pci.0,addr=0x5,drive=drive-virtio- disk0,id=virtio-disk0,bootindex=2,write-cache=on to -device virtio-blk-pci,scsi=off,bus=pci.0,addr=0x5,drive=drive-virtio- disk0,id=virtio-disk0,bootindex=2,write-cache=on I don't get crashes anymore. So for sure it has something to do with iothreads. -- You received this bug notification because you are a member of qemu- devel-ml, which is subscribed to QEMU. https://bugs.launchpad.net/bugs/1793791 Title: Crash with nbd_reply_chunk_iter_receive: Assertion `chunk->flags & NBD_REPLY_FLAG_DONE' failed Status in QEMU: New Bug description: Qemu version on both sides: 2.12.1 Host A Linux: 4.9.76 Host B Linux: 4.14.67 While calling from Host A: virsh migrate virtualmachine qemu+ssh://hostB/system --live --undefinesource --persistent --verbose --copy-storage-all I get a qemu crash with: 2018-09-21 16:12:23.073+0000: 14428: info : virObjectUnref:350 : OBJECT_UNREF: obj=0x7f922c03d990 qemu-system-x86_64: block/nbd-client.c:606: nbd_reply_chunk_iter_receive: Assertion `chunk->flags & NBD_REPLY_FLAG_DONE' failed. 2018-09-21 16:12:41.230+0000: shutting down, reason=crashed 2018-09-21 16:12:52.900+0000: shutting down, reason=failed It doesn't do it every time, but most of the time. To manage notifications about this bug go to: https://bugs.launchpad.net/qemu/+bug/1793791/+subscriptions