base := filepath.Base(name)
		_, err := uuid.Parse(base)
		if err == nil {
			foundDirs[base] = struct{}{}
		}
		return nil
	})
	if err != nil {
		return err
	}
	wantDirs, err := xl.getDataDirs()
	if err != nil {
		return err
	}

	// Delete all directories we expect to be there.
	for _, dir := range wantDirs {
		delete(foundDirs, dir)
	}

	// Delete excessive directories.