 // Truncate the block on the first datanode that has not been corrupted,
    // so that directory scanner can discover the corruption from file size
    // change.
    // the indexes change once the nodes are restarted.
    // But the datadirectory will not change
 // Truncate the block on the first datanode that has not been corrupted,
    // so that directory scanner can discover the corruption from file size
    // change.
    // the indexes change once the nodes are restarted.
    // But the datadirectory will not change | TestProcessCorruptBlocks.java