Dear Liam, You need to upgrade to the latest LTS version of Ubuntu (16.04). I refer to my message to this mailing list on 17/03/2016: Hi everybody, Following this user mailing list over a period of time, I saw a few messages regarding not being able using the external snapshot feature. I refer to this procedure: http://wiki.libvirt.org/page/Live-disk-backup-with-active-blockcommit I would like to mention this hoping it will help those users: Using external snapshots works perfect again in qemu 2.5.0 together with this patch https://bugzilla.redhat.com/show_bug.cgi?id=1300209 Full version list on which I did my testing: Compiled against library: libvirt 1.3.1 Using library: libvirt 1.3.1 Gebruikte API: QEMU 1.3.1 Draaiende hypervisor: QEMU 2.5.0 Greetings, Dominique. *Van:* libvirt-users-bounces(a)redhat.com [mailto: libvirt-users-bounces(a)redhat.com] *Namens *Liam Curtis *Verzonden:* dinsdag 3 mei 2016 17:00 *Aan:* libvirt-users(a)redhat.com *Onderwerp:* [libvirt-users] Ubuntu 14.04 virsh 1.2.2 blockcommit hangs at 100% / command 'blockcommit' doesn't support option --pivot Hello All, I think I have seen this in previous bugs. Trying to live backup qcow2 images. I am able to virsh snapshot-create-as and virsh domblklist shows correct new source, but I am unable to commit back changes to qcow base. I get the above error. Libvirt at 1.2.2-0ubuntu13.1.17 Qemu is (2.0.0+dfsg-2ubuntu1.22) I tried compiling latest libvirt, but cannot get it to connect to socket on installed binaries Anyone get this working on Ubuntu 14.04?