diff --git a/.gitreview b/.gitreview
index 740efa07cf..b4a2ec88e6 100644
--- a/.gitreview
+++ b/.gitreview
@@ -2,4 +2,4 @@
 host=review.opendev.org
 port=29418
 project=openstack/glance.git
-defaultbranch=stable/yoga
+defaultbranch=unmaintained/yoga
diff --git a/glance/common/format_inspector.py b/glance/common/format_inspector.py
index fbd20273be..351c300ddb 100755
--- a/glance/common/format_inspector.py
+++ b/glance/common/format_inspector.py
@@ -567,7 +567,7 @@ def virtual_size(self):
         else:
             vmdktype = b'formatnotfound'
         if vmdktype != b'monolithicSparse':
-            raise ImageFormatError('Unsupported VMDK format %s' % vmdktype)
+            LOG.warning('Unsupported VMDK format %s', vmdktype)
             return 0
 
         # If we have the descriptor, we definitely have the header
diff --git a/glance/tests/unit/common/test_format_inspector.py b/glance/tests/unit/common/test_format_inspector.py
index 4b29c19b30..d229d094fb 100644
--- a/glance/tests/unit/common/test_format_inspector.py
+++ b/glance/tests/unit/common/test_format_inspector.py
@@ -153,6 +153,24 @@ def test_vmdk_invalid(self):
     def test_vdi_invalid(self):
         self._test_format_with_invalid_data('vdi')
 
+    def test_vmdk_invalid_type(self):
+        fmt = format_inspector.get_inspector('vmdk')()
+        wrapper = format_inspector.InfoWrapper(open(__file__, 'rb'), fmt)
+        while True:
+            chunk = wrapper.read(32)
+            if not chunk:
+                break
+
+        wrapper.close()
+
+        fake_rgn = mock.MagicMock()
+        fake_rgn.complete = True
+        fake_rgn.data = b'foocreateType="someunknownformat"bar'
+
+        with mock.patch.object(fmt, 'has_region', return_value=True):
+            with mock.patch.object(fmt, 'region', return_value=fake_rgn):
+                self.assertEqual(0, fmt.virtual_size)
+
 
 class TestFormatInspectorInfra(test_utils.BaseTestCase):
     def _test_capture_region_bs(self, bs):