I updated my system from libvirt 0.7.1 to 0.7.7, one of my qemu-kvm VMs was not starting anymore, with this error: LC_ALL=C PATH=/sbin:/usr/sbin:/bin:/usr/bin HOME=/ TMPDIR=/tmp QEMU_AUDIO_DRV=none /usr/bin/qemu-kvm -S -M pc-0.11 -enable-kvm -m 512 - smp 1,sockets=1,cores=1,threads=1 -name debian-testing -uuid 54f57a86- b84c-61ba-7f2a-c69f39f80a41 -nodefaults -chardev socket,id=monitor,path=/ var/lib/libvirt/qemu/debian-testing.monitor,server,nowait -mon chardev=monitor,mode=readline -rtc base=utc -boot c -drive file=/home/ frederik/Software/iso/debian-testing-amd64- netinst.iso,if=none,media=cdrom,id=drive-ide0-1-0 -device ide- drive,bus=ide.1,unit=0,drive=drive-ide0-1-0,id=ide0-1-0 -drive file=/home/ frederik/VM/debian-testing.img,if=none,id=drive-virtio- disk0,boot=on,format= -device virtio-blk- pci,bus=pci.0,addr=0x4,drive=drive-virtio-disk0,id=virtio-disk0 -device virtio-net-pci,vlan=0,id=net0,mac=52:54:00:25:9c:a0,bus=pci.0,addr=0x5 - net tap,fd=19,vlan=0,name=hostnet0 -chardev pty,id=serial0 -device isa- serial,chardev=serial0 -usb -device usb-tablet,id=input0 -vnc 127.0.0.1:1 -k fr-be -vga vmware -device ES1370,id=sound0,bus=pci.0,addr=0x6 -device virtio-balloon-pci,id=balloon0,bus=pci.0,addr=0x3 char device redirected to /dev/pts/6 qemu: '' invalid format It seems this part of the libvirt xml file was causing the problem: <disk type='file' device='disk'> <driver name='qemu' type=''/> <source file='/home/frederik/VM/debian-testing.img'/> <target dev='vda' bus='virtio'/> <address type='pci' domain='0x0000' bus='0x00' slot='0x04' function='0x0'/> </disk> Notice the empty type parameter in the driver tag. Removing type='' completely, makes the machine start fine. Is this a bug which should be fixed, so that libvirt can deal empty type tags, possible set by older versions? -- Frederik Himpe -- libvir-list mailing list libvir-list@xxxxxxxxxx https://www.redhat.com/mailman/listinfo/libvir-list