class FileJournalManager implements JournalManager {

  @Override
  public void doPreUpgrade() throws IOException {
    LOG.info("Starting upgrade of edits directory " + sd.getRoot());
    try {
     NNUpgradeUtil.doPreUpgrade(conf, sd);
    } catch (IOException ioe) {
     LOG.error("Failed to move aside pre-upgrade storage " +
         "in image directory " + sd.getRoot(), ioe);
     throw ioe;
    }
  }

  public  FileJournalManager(Configuration conf, StorageDirectory sd,
      StorageErrorReporter errorReporter);

}