Correct wrong check of resulting image sparsiness

The check we have in tests for sparsiness is not honest because of the "equal to" part.
The virtual size has to be strictly greater than the content
(as the content is displayed by tools that understand sparseness).

Signed-off-by: Alex Kalenyuk <[email protected]>

Author: akalenyu

tests/framework/pvc.go

@@ -296,10 +296,11 @@ func (f *Framework) VerifySparse(namespace *k8sv1.Namespace, pvc *k8sv1.Persiste
 		return false, err
 	}
 	if info.ActualSize-imageContentSize >= units.MiB {
-		return false, fmt.Errorf("Diff between content size %d and size on disk %d is significant, something's not right", imageContentSize, info.ActualSize)
+		return false, fmt.Errorf("diff between content size %d and size on disk %d is significant, something's not right", imageContentSize, info.ActualSize)
 	}
 	fmt.Fprintf(ginkgo.GinkgoWriter, "INFO: VerifySparse comparison: Virtual: %d vs Content: %d\n", info.VirtualSize, imageContentSize)
-	return info.VirtualSize >= imageContentSize, nil
+	// The content size of a sparse image is significantly lower than the image's virtual size
+	return info.VirtualSize-imageContentSize >= units.MiB, nil
 }
 
 // VerifyFSOverhead checks whether virtual size is smaller than actual size. That means FS Overhead has been accounted for.