diff --git a/.zuul.yaml b/.zuul.yaml
index 4f17959..e5e093a 100644
--- a/.zuul.yaml
+++ b/.zuul.yaml
@@ -209,6 +209,18 @@
     gate:
       jobs:
         - nova-multiattach
+    experimental:
+      jobs:
+        - nova-cells-v1:
+            irrelevant-files:
+              - ^(test-|)requirements.txt$
+              - ^.*\.rst$
+              - ^doc/.*$
+              - ^etc/.*$
+              - ^releasenotes/.*$
+              - ^setup.cfg$
+              - ^tempest/hacking/.*$
+              - ^tempest/tests/.*$
     periodic-stable:
       jobs:
         - tempest-full-queens
diff --git a/releasenotes/notes/fix-show-image-file-expected-code-92d97342d0f6d60e.yaml b/releasenotes/notes/fix-show-image-file-expected-code-92d97342d0f6d60e.yaml
new file mode 100644
index 0000000..a4050a5
--- /dev/null
+++ b/releasenotes/notes/fix-show-image-file-expected-code-92d97342d0f6d60e.yaml
@@ -0,0 +1,6 @@
+---
+fixes:
+  - |
+    Fix show_image_file interface in v2 ImagesClient: Bug#1756264.
+    The expected success code of show_image_file is changed from
+    ``200`` to ``[200, 204, 206]``.
diff --git a/roles/process-stackviz/tasks/main.yaml b/roles/process-stackviz/tasks/main.yaml
index 82f8f3d..3724e0e 100644
--- a/roles/process-stackviz/tasks/main.yaml
+++ b/roles/process-stackviz/tasks/main.yaml
@@ -50,6 +50,7 @@
     - stackviz_archive.stat.exists
     - subunit_input.stat.exists
     - dstat_input.stat.exists
+  failed_when: False
 
 - name: Run stackviz without dstat
   shell: |
@@ -61,3 +62,4 @@
     - stackviz_archive.stat.exists
     - subunit_input.stat.exists
     - not dstat_input.stat.exists
+  failed_when: False
diff --git a/tempest/lib/services/image/v2/images_client.py b/tempest/lib/services/image/v2/images_client.py
index bcdae44..ed6df47 100644
--- a/tempest/lib/services/image/v2/images_client.py
+++ b/tempest/lib/services/image/v2/images_client.py
@@ -161,7 +161,7 @@
         """
         url = 'images/%s/file' % image_id
         resp, body = self.get(url)
-        self.expected_success(200, resp.status)
+        self.expected_success([200, 204, 206], resp.status)
         return rest_client.ResponseBodyData(resp, body)
 
     def add_image_tag(self, image_id, tag):