Re: [libvirt-users] unknown driver format value 'qcow3'

On 04/15/2015 08:13 AM, Jatin Davey wrote: [I'm guessing that you are using something based on RHEL 6, based on how old that version number is...] This version of libvirt does not know how to handle qcow2v3 files. qemu started creating these by default around qemu 2.0 or so, but you can still manually create older qcow2v2 files by specifying: qemu-img create -o compat=0.10 -f qcow2 ... whenever you are manually creating images. With new enough qemu-img, you can also downgrade an image in-place: qemu-img convert -f qcow2 -o compat=0.10 file Or, as you guessed, you can upgrade to newer libvirt that understands the newer format. [For example, basing your distro on RHEL 7, even if you choose to use CentOS instead of RHEL, is a way to get new-enough libvirt] -- Eric Blake eblake redhat com +1-919-301-3266 Libvirt virtualization library http://libvirt.org