To do a live migration for a domU, the back-storage of your virtual machine must be shared storage, like iSCSI , AoE, etc... Setting up AoE is explained at ata-over-ethernet and iSCSI at configure-iscsi-target-linux. To do live migration between two host, these hosts must be on the same subnet, layer 2 network. To make it as easy as possible on each host : First, be sure to properly install Xen on your system, and set up some options, Install_xen_debian. In this example it is assumed that there is already a vm running on host_1. So, here are the steps to do live migration.