[libvirt-users] How to change the default connection of 'virsh' tool from 'qemu' to 'xen' ?

Hi. Thanks to help of this mailing list (especially Jim Fehlig), I have finished setup of libvirt. However, there is something weird. It is that I installed libvirt on 5 servers but the default connection of one of them is 'qemu:///' even if those of the others are all 'xen:///'. I searched how to change it but, I only found a bypass adding " LIBVIRT_DEFAULT_URI='xen:///' " in my .bashrc file. Currently, value of the variable (LIBVIRT_DEFAULT_URI) is set to 'qemu:///'. Since the bypass makes the virtualization type of the server visible 'qemu' to the open stack, I have to change libvirt configuration. I also checked some configure files under '/etc/libvirt', such as libvirt.conf, libvirtd.conf and libxl.conf. But I have no idea, how and what to change. Please give me some advise. It will be a big help for me. Thanks.