fog--fog/lib/fog/libvirt/models/compute/templates/volume.xml.erb

<volume>
        <name><%= name %></name>
        <allocation unit="<%= allocation_unit %>"><%= allocation_size %>"></allocation>
        <capacity unit="<%= capacity_unit %>"><%= capacity_size %>"></capacity>
        <target>
          <format type="<%= format_type %>"/>
          <permissions>
            <owner>0</owner>
            <group>0</group>
            <mode>0744</mode>
            <label>virt_image_t</label>
          </permissions>
        </target>
</volume>