Hi all, I use "ubuntu hardy" but I dont think the problem is specific to the distribution I use. I installed KVM and libvirt as described here: https://help.ubuntu.com/community/KVM Following that method, created a domain, which dumps like this: <domain type='qemu' id='1'> <name>xp1</name> ... </domain> Launching the guest is OK, but it is as slow as if I directly launched $ qemu [options] I tried to launch: $ kvm [options] and it is much faster My conclusion is that method on the Ubuntu documentation launches a qemu without the use of kvm. I modified that XML dump, changing "qemu" with "kvm": <domain type='kvm' id='1'> <name>xp1</name> ... </domain> I undefined the domain "xp1" and re-defined it with that new XML file. When I start the new defined domain: virsh # start xp1 libvir: QEMU error : QEMU quit during console startup qemu: unknowm parameter 'boot' in \ 'file=/home/mihamina/xpjohnny.iso,if=ide,media=cdrom,boot=on' error: Failed to start domain xp1 It's a Windows XP domain. My conclusion is: - When domain type is "qemu", qemu is called a certain way, without syntax error - When domain type is "kvm", qemu/kvm is not called the same way and among that, there are syntax errors. How to confirm my conclusion? What to check if it's the case? I already filed a bug https://bugs.launchpad.net/ubuntu/+source/libvirt/+bug/252916 but they seem not to have idea of the problem. -- Huile Essentielle de Camphre http://www.huile-camphre.fr Infogerance http://www.infogerance.us (Serveurs, Postes de travail, Développement logiciel)