[libvirt] kvm migration

Hi, can someone explain me how migration works in libvirt? I got 2 machines with ubuntu 9.04 (libvirt 0.6.1 and kvm 84), disk images are stored on nfs share so both machines can access them. When I run live migration (virsh migrate --live domain uri) my domain is migrated to second host but: 1. domain is defined on both hosts after migration, it does not disappear from original host 2. when I shutdown this domain on second host it gets undefined so I guess that migration is only temporary but this is not what I want. When I migrate domain to other host I want it to stay there, how can I do that? I can't find anything about it in documentation on libvirt website, google does not seem to know anything either. Łukasz Mierzwa