@@ -29,6 +29,7 @@ type saveSession struct {

 	outDir      string

 	images      map[image.ID]*imageDescriptor

 	savedLayers map[string]struct{}

+	diffIDPaths map[layer.DiffID]string // cache every diffID blob to avoid duplicates

 }

 func (l *tarexporter) Save(names []string, outStream io.Writer) error {

@@ -117,6 +118,7 @@ func (l *tarexporter) parseNames(names []string) (map[image.ID]*imageDescriptor,

 func (s *saveSession) save(outStream io.Writer) error {

 	s.savedLayers = make(map[string]struct{})

+	s.diffIDPaths = make(map[layer.DiffID]string)

 	// get image json

 	tempDir, err := ioutil.TempDir("", "docker-export-")

@@ -297,35 +299,46 @@ func (s *saveSession) saveLayer(id layer.ChainID, legacyImg image.V1Image, creat

 	}

 	// serialize filesystem

-	tarFile, err := os.Create(filepath.Join(outDir, legacyLayerFileName))

-	if err != nil {

-		return distribution.Descriptor{}, err

-	}

-	defer tarFile.Close()

-

+	layerPath := filepath.Join(outDir, legacyLayerFileName)

 	l, err := s.ls.Get(id)

 	if err != nil {

 		return distribution.Descriptor{}, err

 	}

 	defer layer.ReleaseAndLog(s.ls, l)

-	arch, err := l.TarStream()

-	if err != nil {

-		return distribution.Descriptor{}, err

-	}

-	defer arch.Close()

+	if oldPath, exists := s.diffIDPaths[l.DiffID()]; exists {

+		relPath, err := filepath.Rel(layerPath, oldPath)

+		if err != nil {

+			return distribution.Descriptor{}, err

+		}

+		os.Symlink(relPath, layerPath)

+	} else {

-	if _, err := io.Copy(tarFile, arch); err != nil {

-		return distribution.Descriptor{}, err

-	}

+		tarFile, err := os.Create(layerPath)

+		if err != nil {

+			return distribution.Descriptor{}, err

+		}

+		defer tarFile.Close()

-	for _, fname := range []string{"", legacyVersionFileName, legacyConfigFileName, legacyLayerFileName} {

-		// todo: maybe save layer created timestamp?

-		if err := system.Chtimes(filepath.Join(outDir, fname), createdTime, createdTime); err != nil {

+		arch, err := l.TarStream()

+		if err != nil {

 			return distribution.Descriptor{}, err

 		}

-	}

+		defer arch.Close()

+

+		if _, err := io.Copy(tarFile, arch); err != nil {

+			return distribution.Descriptor{}, err

+		}

+

+		for _, fname := range []string{"", legacyVersionFileName, legacyConfigFileName, legacyLayerFileName} {

+			// todo: maybe save layer created timestamp?

+			if err := system.Chtimes(filepath.Join(outDir, fname), createdTime, createdTime); err != nil {

+				return distribution.Descriptor{}, err

+			}

+		}

+		s.diffIDPaths[l.DiffID()] = layerPath

+	}

 	s.savedLayers[legacyImg.ID] = struct{}{}

 	var src distribution.Descriptor