I was using a disco guest this time (as I tried B before to cover more variants) Note: the libvirt in disco realizes we are doing tricky bullshit (withotu shared storage), but since we know it works we set --unsafe to force it trying the migration C->X and it works. Without fix: 1. migrate Xenial -> Cosmic $ virsh migrate --live --verbose --copy-storage-all disco-migrate qemu+ssh://10.245.71.165/system setlocale: No such file or directory The authenticity of host '10.245.71.165 (10.245.71.165)' can't be established. ECDSA key fingerprint is SHA256:USOw9WaJkZbtcHayQX5AnfKYRpCCPQYvGYXxoVphop8. Are you sure you want to continue connecting (yes/no)? yes Migration: [100 %] 2. migrate Cosmic -> Xenial $ virsh migrate --live --verbose --unsafe disco-migrate qemu+ssh://10.245.71.187/system Migration: [100 %]error: operation failed: job: unexpectedly failed In the logs I find: source: 019-02-07 09:18:40.005+0000: initiating migration target: 2019-02-07T09:18:44.431313Z qemu-system-ppc64: error while loading state for instance 0x0 of device 'cpu' 2019-02-07T09:18:44.432060Z qemu-system-ppc64: load of migration failed: Invalid argument Installing Cosmic qemu from proposed worked fine $ sudo apt install $(apt list --upgradable 2>&1 | awk '/^qemu/ {gsub("/.*",""); print $0}' | xargs) Reading package lists... Done Building dependency tree Reading state information... Done Suggested packages: samba vde2 openbios-ppc openhackware debootstrap The following packages will be upgraded: qemu-block-extra qemu-kvm qemu-system-common qemu-system-data qemu-system-gui qemu-system-ppc qemu-utils 7 upgraded, 0 newly installed, 0 to remove and 16 not upgraded. Need to get 10.3 MB of archives. After this operation, 0 B of additional disk space will be used. Get:1 http://ports.ubuntu.com/ubuntu-ports cosmic-proposed/main ppc64el qemu-utils ppc64el 1:2.12+dfsg-3ubuntu8.3 [1055 kB] Get:2 http://ports.ubuntu.com/ubuntu-ports cosmic-proposed/main ppc64el qemu-system-common ppc64el 1:2.12+dfsg-3ubuntu8.3 [32.4 kB] Get:3 http://ports.ubuntu.com/ubuntu-ports cosmic-proposed/main ppc64el qemu-block-extra ppc64el 1:2.12+dfsg-3ubuntu8.3 [42.4 kB] Get:4 http://ports.ubuntu.com/ubuntu-ports cosmic-proposed/main ppc64el qemu-system-data all 1:2.12+dfsg-3ubuntu8.3 [703 kB] Get:5 http://ports.ubuntu.com/ubuntu-ports cosmic-proposed/main ppc64el qemu-kvm ppc64el 1:2.12+dfsg-3ubuntu8.3 [12.7 kB] Get:6 http://ports.ubuntu.com/ubuntu-ports cosmic-proposed/main ppc64el qemu-system-ppc ppc64el 1:2.12+dfsg-3ubuntu8.3 [8429 kB] Get:7 http://ports.ubuntu.com/ubuntu-ports cosmic-proposed/main ppc64el qemu-system-gui ppc64el 1:2.12+dfsg-3ubuntu8.3 [35.0 kB] Fetched 10.3 MB in 7s (1440 kB/s) (Reading database ... 114642 files and directories currently installed.) Preparing to unpack .../0-qemu-utils_1%3a2.12+dfsg-3ubuntu8.3_ppc64el.deb ... Unpacking qemu-utils (1:2.12+dfsg-3ubuntu8.3) over (1:2.12+dfsg-3ubuntu8.2) ... Preparing to unpack .../1-qemu-system-common_1%3a2.12+dfsg-3ubuntu8.3_ppc64el.deb ... Unpacking qemu-system-common (1:2.12+dfsg-3ubuntu8.3) over (1:2.12+dfsg-3ubuntu8.2) ... Preparing to unpack .../2-qemu-block-extra_1%3a2.12+dfsg-3ubuntu8.3_ppc64el.deb ... Unpacking qemu-block-extra:ppc64el (1:2.12+dfsg-3ubuntu8.3) over (1:2.12+dfsg-3ubuntu8.2) ... Preparing to unpack .../3-qemu-system-data_1%3a2.12+dfsg-3ubuntu8.3_all.deb ... Unpacking qemu-system-data (1:2.12+dfsg-3ubuntu8.3) over (1:2.12+dfsg-3ubuntu8.2) ... Preparing to unpack .../4-qemu-kvm_1%3a2.12+dfsg-3ubuntu8.3_ppc64el.deb ... Unpacking qemu-kvm (1:2.12+dfsg-3ubuntu8.3) over (1:2.12+dfsg-3ubuntu8.2) ... Preparing to unpack .../5-qemu-system-ppc_1%3a2.12+dfsg-3ubuntu8.3_ppc64el.deb ... Unpacking qemu-system-ppc (1:2.12+dfsg-3ubuntu8.3) over (1:2.12+dfsg-3ubuntu8.2) ... Preparing to unpack .../6-qemu-system-gui_1%3a2.12+dfsg-3ubuntu8.3_ppc64el.deb ... Unpacking qemu-system-gui (1:2.12+dfsg-3ubuntu8.3) over (1:2.12+dfsg-3ubuntu8.2) ... Setting up qemu-system-data (1:2.12+dfsg-3ubuntu8.3) ... Setting up qemu-block-extra:ppc64el (1:2.12+dfsg-3ubuntu8.3) ... Setting up qemu-utils (1:2.12+dfsg-3ubuntu8.3) ... Processing triggers for man-db (2.8.4-2) ... Setting up qemu-system-gui (1:2.12+dfsg-3ubuntu8.3) ... Setting up qemu-system-common (1:2.12+dfsg-3ubuntu8.3) ... Setting up qemu-system-ppc (1:2.12+dfsg-3ubuntu8.3) ... Setting up qemu-kvm (1:2.12+dfsg-3ubuntu8.3) ... Retest the above 1. migrate Xenial -> Cosmic $ virsh migrate --live --verbose --copy-storage-inc disco-migrate qemu+ssh://10.245.71.165/system setlocale: No such file or directory Migration: [100 %] 2. migrate Cosmic -> Xenial $ virsh migrate --live --verbose --unsafe disco-migrate qemu+ssh://10.245.71.187/system Migration: [100 %] The guests logs are clean: source: 9-02-07 09:25:56.185+0000: initiating migration 2019-02-07 09:26:00.705+0000: shutting down, reason=migrated 2019-02-07T09:26:00.706632Z qemu-system-ppc64: terminating on signal 15 from pid 3868 (/usr/sbin/libvirtd) target: (a starting qemu, nothing else) Thereby setting verified for cosmic