Re: [libvirt] messed up with xml-files and configuration of a VM

first, i'm new to kvm. I'm running KVM on a sles 11 sp2, kernel 3.0.13-0.27-default. My guest is an Ubuntu 12.0.4 LTS 64bit. The guest has attached a CDROM, using an iso-file from a CIFS-Share. I detached it with the virtual machine manager (0.9.0). I don't see the cd-rom anymore in the virtual machine manager. But when i try to start the vm, it complains about the missing iso-file. Why ? I detached it. When i like to have a look in the xml-files of the guest, i found three ! One in /var/lib/kvm/images, one in /etc/libvirt/qemu and one in /etc/kvm/vm. Which one should i use to configure the vm ? In the one in /etc/libvirt/qemu the cifs-share isn't mentioned any longer, in the other two it is still. Is it possible to configure the vm editing one of the XML-files ? Or shall i use virsh ? Using virsh, does the vm has to be stopped or can i edit the configuration for a running vm ? Why three xml-files ? Why is detaching with the virtual machine manager not working ?