@Override
  protected void addOptions() {
    addRequiredOption(Options.SNAPSHOT);
    addOption(Options.COPY_TO);
    addOption(Options.COPY_FROM);
    addOption(Options.TARGET_NAME);
    addOption(Options.NO_CHECKSUM_VERIFY);
    addOption(Options.NO_TARGET_VERIFY);
    addOption(Options.NO_SOURCE_VERIFY);
    addOption(Options.OVERWRITE);
    addOption(Options.CHUSER);
    addOption(Options.CHGROUP);
    addOption(Options.CHMOD);
    addOption(Options.MAPPERS);
    addOption(Options.BANDWIDTH);
    addOption(Options.RESET_TTL);
  }
Execute the export snapshot by copying the snapshot metadata, hfiles and wals.
@return 0 on success, and != 0 upon failure.
hbase-mapreduce/src/main/java/org/apache/hadoop/hbase/snapshot/ExportSnapshot.java