code: private void checkFreeDiskSpace(List<File> inputFiles) {
      //Check for free space
      long usableSpace = 0;
      long totalSize = 0;
      for (File f : inputFiles) {
        if (f.exists()) {
          totalSize += f.length();
          usableSpace = f.getUsableSpace();
        }
      }
      LOGGER.log(Level.INFO, "Total expected store size is {0} Mb",
          new DecimalFormat("#,##0.0").format(totalSize / (1024 * 1024)));
      LOGGER.log(Level.INFO, "Usable free space on the system is {0} Mb",
          new DecimalFormat("#,##0.0").format(usableSpace / (1024 * 1024)));
      if (totalSize / (double) usableSpace >= 0.66) {
        throw new RuntimeException("Aborting because there isn' enough free disk space");
      }
    }
docs: Fail if the size of the expected store file exceed 2/3rd of the free disk space