For now, i'm using something like workaround for this problem, may be it will be useful for someone. basic idea is - using some 12.04 host as transit one, which will take VMs from other 12.04 online, then will have libvirt & kvm upgraded , restart of VMs (usually 1-2 mins), then can be moved online to 14.04 host
on transit host, 12.04 install, latest updates, without any VMs yet: into /etc/default/grub set GRUB_CMDLINE_LINUX_DEFAULT="rootdelay=90" # update-grub first, let's make reverting easy with snapshotting / partition (you may need to add /var if it is separated) lvcreate -n rootfspv -L 50G shared pvcreate /dev/shared/rootfspv vgextend system /dev/shared/rootfspv lvcreate -n rootfssnap -s -L 30G system/root configure libvirt to accept migration migrate VMs to such transit host # for i in $(virsh list |grep runn|awk '{print $2}'|xargs echo);do virsh edit $i;done here we should set cache to none, if u are using lvm as storage, to look like: <driver name='qemu' type='raw' cache='none'/> then, upgrading set sources.list to trusty , #apt-get update #apt-get install qemu-kvm libvirt-bin librbd1 (i answered no to all requests for configs update) checking all is going fine: qemu-system-x86_64 -machine help output should be regular, like root@hw06:~# qemu-system-x86_64 -machine help Supported machines are: pc-0.13 Standard PC (i440FX + PIIX, 1996) pc-i440fx-2.0 Standard PC (i440FX + PIIX, 1996) pc-1.0-qemu-kvm Standard PC (i440FX + PIIX, 1996) (alias of pc-1.0) restart libvirt: #service libvirt-bin restart checking is ok #virsh list --all #apt-get install apparmor-utils #aa-disable /etc/apparmor.d/usr.sbin.libvirtd #service libvirt-bin restart checking is ok #virsh list --all the next step is restart VMs and later they can be migrated to 14.04 online reverting back to 12.04: removing VMs disks: #lvremove /dev/shared/* reverting snapshot: #lvconvert --merge /dev/system/rootfssnap #reboot after boot check there are no snapshots left, if yes, you should reboot one more time (is needed sometimes) next group can be moved now -- You received this bug notification because you are a member of Ubuntu Bugs, which is subscribed to Ubuntu. https://bugs.launchpad.net/bugs/1477488 Title: live migration for KVM VM via libvirt from 12.04 to 14.04 fails , unable to change machine type to pc-1.0-precise To manage notifications about this bug go to: https://bugs.launchpad.net/ubuntu/+source/libvirt/+bug/1477488/+subscriptions -- ubuntu-bugs mailing list ubuntu-bugs@lists.ubuntu.com https://lists.ubuntu.com/mailman/listinfo/ubuntu-bugs