diff --git a/qa/rbd/krbd_parent_overlap.t b/qa/rbd/krbd_parent_overlap.t
index 47deda90e4b..a113311b4a9 100644
--- a/qa/rbd/krbd_parent_overlap.t
+++ b/qa/rbd/krbd_parent_overlap.t
@@ -1,22 +1,27 @@
 
 For reads, only the object extent needs to be reverse mapped:
 
-  $ rbd create --size 20M img
+  $ rbd create --size 5M img
   $ DEV=$(sudo rbd map img)
-  $ xfs_io -c 'pwrite 0 20M' $DEV >/dev/null
+  $ xfs_io -c 'pwrite 0 5M' $DEV >/dev/null
   $ sudo rbd unmap $DEV
   $ rbd snap create img@snap
   $ rbd snap protect img@snap
   $ rbd clone img@snap cloneimg
-  $ rbd resize --no-progress --size 5M --allow-shrink cloneimg
-  $ rbd resize --no-progress --size 20M cloneimg
+  $ rbd resize --no-progress --size 12M cloneimg
   $ DEV=$(sudo rbd map cloneimg)
   $ hexdump $DEV
   0000000 cdcd cdcd cdcd cdcd cdcd cdcd cdcd cdcd
   *
   0500000 0000 0000 0000 0000 0000 0000 0000 0000
   *
-  1400000
+  0c00000
+  $ dd if=$DEV iflag=direct bs=4M status=none | hexdump
+  0000000 cdcd cdcd cdcd cdcd cdcd cdcd cdcd cdcd
+  *
+  0500000 0000 0000 0000 0000 0000 0000 0000 0000
+  *
+  0c00000
   $ sudo rbd unmap $DEV
   $ rbd rm --no-progress cloneimg
   $ rbd snap unprotect img@snap