Tried using direct kernel boot with QEMU and couldn't reproduce it: sha256sum /mnt/libvirt-images/boot-resources-20190419-115735/snapshot-20190419-115735/ubuntu/amd64/generic/bionic/daily/boot-initrd 69ca457a119fe309d315972ca2756a17bd9bc55bc98f2bea5542566a7f41b08f /mnt/libvirt-images/boot-resources-20190419-115735/snapshot-20190419-115735/ubuntu/amd64/generic/bionic/daily/boot-initrd 30463 qemu-system-x86_64 -enable-kvm -name guest=maas-vhost6,debug-threads=on -S -object secret,id=masterKey0,format=raw,file=/var/lib/libvirt/qemu/domain-224-maas-vhost6/master-key.aes -machine pc-q35-2.11,accel=kvm,usb=off,vmport=off,dump-guest-core=off -cpu Haswell-noTSX-IBRS,vme=on,ss=on,vmx=on,f16c=on,rdrand=on,hypervisor=on,arat=on,tsc_adjust=on,ssbd=on,xsaveopt=on,pdpe1gb=on,abm=on -m 2048 -realtime mlock=off -smp 2,sockets=2,cores=1,threads=1 -uuid 399eae83-f059-4ac0-9609-5bb548f5a90a -no-user-config -nodefaults -chardev socket,id=charmonitor,path=/var/lib/libvirt/qemu/domain-224-maas-vhost6/monitor.sock,server,nowait -mon chardev=charmonitor,id=monitor,mode=control -rtc base=utc,driftfix=slew -global kvm-pit.lost_tick_policy=delay -no-hpet -no-shutdown -global ICH9-LPC.disable_s3=1 -global ICH9-LPC.disable_s4=1 -boot strict=on -kernel /mnt/libvirt-images/boot-resources-20190419-115735/snapshot-20190419-115735/ubuntu/amd64/generic/bionic/daily/boot-kernel -initrd /mnt/libvirt-images/boot-resources-20190419-115735/snapshot-20190419-115735/ubuntu/amd64/generic/bionic/daily/boot-initrd -append BOOT_IMAGE=http://10.10.101.2:5248/images/ubuntu/amd64/ga-18.04/bionic/daily/boot-kernel nomodeset ro root=squash:http://10.10.101.2:5248/images/ubuntu/amd64/ga-18.04/bionic/daily/squashfs ip=::::maas-vhost6:BOOTIF ip6=off overlayroot=tmpfs overlayroot_cfgdisk=disabled cc:{'datasource_list': ['MAAS']}end_cc cloud-config-url=http://10.10.101.2:5248/MAAS/metadata/latest/by-id/xeqrrw/?op=get_preseed apparmor=0 log_host=10.10.101.2 log_port=5247 --- console=ttyS0,115200 initrd=http://10.10.101.2:5248/images/ubuntu/amd64/ga-18.04/bionic/daily/boot-initrd BOOTIF=01-52-54-00-3f-ae-46 -device pcie-root-port,port=0x10,chassis=1,id=pci.1,bus=pcie.0,multifunction=on,addr=0x2 -device pcie-root-port,port=0x11,chassis=2,id=pci.2,bus=pcie.0,addr=0x2.0x1 -device pcie-root-port,port=0x12,chassis=3,id=pci.3,bus=pcie.0,addr=0x2.0x2 -device pcie-root-port,port=0x13,chassis=4,id=pci.4,bus=pcie.0,addr=0x2.0x3 -device pcie-root-port,port=0x14,chassis=5,id=pci.5,bus=pcie.0,addr=0x2.0x4 -device pcie-root-port,port=0x15,chassis=6,id=pci.6,bus=pcie.0,addr=0x2.0x5 -device pcie-root-port,port=0x16,chassis=7,id=pci.7,bus=pcie.0,addr=0x2.0x6 -device i82801b11-bridge,id=pci.8,bus=pcie.0,addr=0x1e -device pci-bridge,chassis_nr=9,id=pci.9,bus=pci.8,addr=0x0 -device ich9-usb-ehci1,id=usb,bus=pcie.0,addr=0x1d.0x7 -device ich9-usb-uhci1,masterbus=usb.0,firstport=0,bus=pcie.0,multifunction=on,addr=0x1d -device ich9-usb-uhci2,masterbus=usb.0,firstport=2,bus=pcie.0,addr=0x1d.0x1 -device ich9-usb-uhci3,masterbus=usb.0,firstport=4,bus=pcie.0,addr=0x1d.0x2 -device virtio-scsi-pci,id=scsi0,bus=pci.2,addr=0x0 -device virtio-scsi-pci,id=scsi1,bus=pci.4,addr=0x0 -device ahci,id=sata1,bus=pci.9,addr=0x1 -device ahci,id=sata2,bus=pci.9,addr=0x2 -device virtio-serial-pci,id=virtio-serial0,bus=pci.3,addr=0x0 -drive file=/mnt/libvirt-images/vhost6.qcow2,format=qcow2,if=none,id=drive-scsi0-0-0-0 -device scsi-hd,bus=scsi0.0,channel=0,scsi-id=0,lun=0,drive=drive-scsi0-0-0-0,id=scsi0-0-0-0,bootindex=2 -drive file=/mnt/libvirt-images/maas-vhost6.qcow2,format=qcow2,if=none,id=drive-scsi0-0-0-1,serial=disk0 -device scsi-hd,bus=scsi0.0,channel=0,scsi-id=0,lun=1,drive=drive-scsi0-0-0-1,id=scsi0-0-0-1 -drive file=/mnt/libvirt-images/masa-vhost6-scsi21.qcow2,format=qcow2,if=none,id=drive-scsi1-0-0-2,serial=disk1 -device scsi-hd,bus=scsi1.0,channel=0,scsi-id=0,lun=2,drive=drive-scsi1-0-0-2,id=scsi1-0-0-2 -drive file=/mnt/libvirt-images/maas-vhost6-virtio0.qcow2,format=qcow2,if=none,id=drive-virtio-disk0 -device virtio-blk-pci,scsi=off,bus=pci.6,addr=0x0,drive=drive-virtio-disk0,id=virtio-disk0 -drive file=/mnt/libvirt-images/maas-vhost6-virtio1.qcow2,format=qcow2,if=none,id=drive-virtio-disk1,serial=disk3 -device virtio-blk-pci,scsi=off,bus=pci.7,addr=0x0,drive=drive-virtio-disk1,id=virtio-disk1 -drive file=/mnt/libvirt-images/maas-vhost6-sata0.qcow2,format=qcow2,if=none,id=drive-sata0-0-3,serial=disk4 -device ide-hd,bus=ide.3,drive=drive-sata0-0-3,id=sat virsh dumpxml exempt: hvm /mnt/libvirt-images/boot-resources-20190419-115735/snapshot-20190419-115735/ubuntu/amd64/generic/bionic/daily/boot-kernel /mnt/libvirt-images/boot-resources-20190419-115735/snapshot-20190419-115735/ubuntu/amd64/generic/bionic/daily/boot-initrd BOOT_IMAGE=http://10.10.101.2:5248/images/ubuntu/amd64/ga-18.04/bionic/daily/boot-kernel nomodeset ro root=squash:http://10.10.101.2:5248/images/ubuntu/amd64/ga-18.04/bionic/daily/squashfs ip=::::maas-vhost6:BOOTIF ip6=off overlayroot=tmpfs overlayroot_cfgdisk=disabled cc:{'datasource_list': ['MAAS']}end_cc cloud-config-url=http://10.10.101.2:5248/MAAS/metadata/latest/by-id/xeqrrw/?op=get_preseed apparmor=0 log_host=10.10.101.2 log_port=5247 --- console=ttyS0,115200 initrd=http://10.10.101.2:5248/images/ubuntu/amd64/ga-18.04/bionic/daily/boot-initrd BOOTIF=01-52-54-00-3f-ae-46