diff --git a/releasenotes/notes/change-default-disk-format-0d5230cbb19e3d44.yaml b/releasenotes/notes/change-default-disk-format-0d5230cbb19e3d44.yaml
new file mode 100644
index 0000000..57c5319
--- /dev/null
+++ b/releasenotes/notes/change-default-disk-format-0d5230cbb19e3d44.yaml
@@ -0,0 +1,8 @@
+---
+upgrade:
+  - |
+    The default value for ``[volume] disk_format``, which specifies the
+    disk format of the image in a copy a volume to image operation,
+    is changed from ``raw`` to ``[raw, qcow2]`` for which the type of
+    the config option also needed to change from ``string`` type to
+    ``list`` type i.e. it accepts multiple values now.