diff --git a/nova/tests/unit/virt/libvirt/test_driver.py b/nova/tests/unit/virt/libvirt/test_driver.py
index e482e02914e0..47dd0875fc1a 100644
--- a/nova/tests/unit/virt/libvirt/test_driver.py
+++ b/nova/tests/unit/virt/libvirt/test_driver.py
@@ -7718,7 +7718,8 @@ class LibvirtConnTestCase(test.NoDBTestCase,
         mock_dom = mock.MagicMock()
 
         # Second time don't return anything about disk vdc so it looks removed
-        return_list = [mock_xml_with_disk, mock_xml_without_disk]
+        return_list = [mock_xml_with_disk, mock_xml_without_disk,
+                       mock_xml_without_disk]
         # Doubling the size of return list because we test with two guest power
         # states
         mock_dom.XMLDesc.side_effect = return_list + return_list
@@ -19240,7 +19241,7 @@ class LibvirtDriverTestCase(test.NoDBTestCase):
             # DeviceNotFound
             get_interface_calls = [expected_cfg, None]
         else:
-            get_interface_calls = [expected_cfg, expected_cfg, None]
+            get_interface_calls = [expected_cfg, expected_cfg, None, None]
 
         with test.nested(
             mock.patch.object(host.Host, 'get_guest', return_value=guest),
@@ -19377,7 +19378,7 @@ class LibvirtDriverTestCase(test.NoDBTestCase):
         domain.detachDeviceFlags(expected.to_xml(), flags=expected_flags)
         self.mox.ReplayAll()
         with mock.patch.object(libvirt_guest.Guest, 'get_interface_by_cfg',
-                               side_effect=[expected, expected, None]):
+                               side_effect=[expected, expected, None, None]):
             self.drvr.detach_interface(self.context, instance, network_info[0])
         self.mox.VerifyAll()
 
diff --git a/nova/tests/unit/virt/libvirt/test_guest.py b/nova/tests/unit/virt/libvirt/test_guest.py
index 1598e3ceb82f..c25ef77b559d 100644
--- a/nova/tests/unit/virt/libvirt/test_guest.py
+++ b/nova/tests/unit/virt/libvirt/test_guest.py
@@ -228,7 +228,7 @@ class GuestTestCase(test.NoDBTestCase):
         conf = mock.Mock(spec=vconfig.LibvirtConfigGuestDevice)
         conf.to_xml.return_value = "</xml>"
         get_config = mock.Mock()
-        get_config.side_effect = [conf, conf, None]
+        get_config.side_effect = [conf, conf, conf, None, None]
         dev_path = "/dev/vdb"
         self.domain.isPersistent.return_value = False
         retry_detach = self.guest.detach_device_with_retry(
@@ -244,7 +244,7 @@ class GuestTestCase(test.NoDBTestCase):
         conf.to_xml.return_value = "</xml>"
         get_config = mock.Mock()
         # Force multiple retries of detach
-        get_config.side_effect = [conf, conf, conf, None]
+        get_config.side_effect = [conf, conf, conf, conf, conf, None, None]
         dev_path = "/dev/vdb"
         self.domain.isPersistent.return_value = True
 
@@ -334,7 +334,7 @@ class GuestTestCase(test.NoDBTestCase):
         get_config = mock.Mock()
         # Simulate the persistent domain attach attempt followed by the live
         # domain attach attempt and success
-        get_config.side_effect = [conf, conf, None]
+        get_config.side_effect = [conf, conf, conf, None, None]
         fake_device = "vdb"
         fake_exc = fakelibvirt.make_libvirtError(
             fakelibvirt.libvirtError, "",
diff --git a/nova/virt/libvirt/guest.py b/nova/virt/libvirt/guest.py
index ab9746b442fb..42bc26495e15 100644
--- a/nova/virt/libvirt/guest.py
+++ b/nova/virt/libvirt/guest.py
@@ -395,9 +395,11 @@ class Guest(object):
             # Raise DeviceNotFound if the device isn't found during detach
             try:
                 self.detach_device(conf, persistent=persistent, live=live)
-                LOG.debug('Successfully detached device %s from guest. '
-                          'Persistent? %s. Live? %s',
-                          device, persistent, live)
+                if get_device_conf_func(device) is None:
+                    LOG.debug('Successfully detached device %s from guest. '
+                              'Persistent? %s. Live? %s',
+                              device, persistent, live)
+
             except libvirt.libvirtError as ex:
                 with excutils.save_and_reraise_exception():
                     errcode = ex.get_error_code()
@@ -448,11 +450,11 @@ class Guest(object):
         def _do_wait_and_retry_detach():
             config = get_device_conf_func(device)
             if config is not None:
-                # Device is already detached from persistent domain
-                # and only transient domain needs update
+                # Device is already detached from persistent config
+                # and only the live config needs to be updated.
                 _try_detach_device(config, persistent=False, live=live)
 
-                reason = _("Unable to detach from guest transient domain.")
+                reason = _("Unable to detach the device from the live config.")
                 raise exception.DeviceDetachFailed(
                     device=alternative_device_name, reason=reason)