<on_reboot>restart</on_reboot>
   <on_crash>destroy</on_crash>
   <devices>
+    <disk type="file" device="disk">
+      <driver name="qemu" type="qcow2"/>
+      <source file="/pool-dir/testvol1.img"/>
+      <target dev="vda" bus="virtio"/>
+    </disk>
   </devices>
+  <metadata>
+    <libosinfo:libosinfo xmlns:libosinfo="http://libosinfo.org/xmlns/libvirt/domain/1.0">
+      <libosinfo:os id="http://fedoraproject.org/fedora/28"/>
+    </libosinfo:libosinfo>
+  </metadata>
 </domain>

Domain 'test' defined successfully.
Changes will take effect after the domain is fully powered off.