It seems virsh 0.8.3 cannot connect to libvirtd 0.6.3. Machine 1: iibvirtd is 0.6.3 Machine 2: virsh 0.6.1 virsh -c xen+ssh://root@192.168.1.78 list Connecting to uri: qemu:///session Id Name State ---------------------------------- 0 Domain-0 running 1 shanxi idle Machine 3: virsh 0.8.3 virsh -c xen+ssh://root@192.168.1.78 list error: server closed connection: error: failed to connect to the hypervisor