Increase buffer size and only compare section of the buffer that's actually used

drive-demuxer.go

@@ -119,6 +119,10 @@ func (s *Step) SeparateRight(child string) {
 	rightInPath := s.InputPath(child, RIGHT)
 	rightOutPath := s.OutputPath(child, RIGHT)
 
+	if s.DryRun {
+		return
+	}
+
 	rightBase := path.Dir(rightOutPath)
 	err := os.MkdirAll(rightBase, 0755)
 	if err != nil {
@@ -135,6 +139,10 @@ func (s *Step) Combine(child string) {
 	rightInPath := s.InputPath(child, RIGHT)
 	combinedOutPath := s.OutputPath(child, COMBINED)
 
+	if s.DryRun {
+		return
+	}
+
 	combinedBase := path.Dir(combinedOutPath)
 	err := os.MkdirAll(combinedBase, 0755)
 	if err != nil {