Hi, all My xml 'dom1.xml' is as following: <domain type='kvm' id='1'> <name>kvm-xp</name> <description>xp kvm</description> <memory>524288</memory> <currentMemory>524288</currentMemory> <os> <type>hvm</type> <!--loader>/usr/lib/xen/boot/hvmloader</loader--> <boot dev="hd"/> </os> <devices> <disk type='file'> <source file='/home/eucalyptus/imgs/xp.img'/> <target dev='hda' bus='ide'/> </disk> <driver name='qemu' type='qcow2'/> <!--graphics type="sdl" display=':0.0'/--> <!--graphics type="desktop" fullscreen='yes'/--> <graphics type='vnc' port='5904'/> </devices> </domain> In this xml file, I don't know how to set disk file format to 'qcow2'. When I create domain using this command: virsh create dom1.xml I cannot boot the image file. The log file /var/log/libvirt/qemu/kvm-xp.log is as following: LC_ALL=C PATH=/bin:/sbin:/usr/bin:/usr/sbin:/usr/local/sbin:/usr/local/sbin:/usr/local/bin:/usr/sbin:/usr/bin:/sbin:/bin:/opt/bin:/usr/x86_64-pc-linux-gnu/gcc-bin/4.4.3 HOME=/root USER=root QEMU_AUDIO_DRV=none /usr/bin/kvm -S -M pc -m 512 -smp 1 -name kvm-xp -uuid a8cbae31-59a0-0bc5-4416-65ba63aa4231 -monitor unix:/var/lib/libvirt/qemu/kvm-xp.monitor,server,nowait -no-acpi -boot c -drive file=/home/eucalyptus/imgs/xp.img,if=ide,bus=0,unit=0,format=raw -net none -serial none -parallel none -usb -vnc 127.0.0.1:4 -vga cirrus -balloon virtio I don't know how to set format argument to 'qcow2' ---------------- Xiaodong Jiang jxd431@xxxxxxxxx