参考书籍：《Hadoop实战》第二版 第9章:HDFS详解

1. HDFS基本操作

@ 出现的bug信息

@-@ WARN util.NativeCodeLoader: Unable to load native-hadoop library for your platform... using builtin-java classes where applicable

@-@ WARN hdfs.DFSClient: DFSInputStream has been closed already

@ Hadoop调试信息的开启与关闭

开启：export HADOOP_ROOT_LOGGER=DEBUG,console

关闭：export HADOOP_ROOT_LOGGER=INFO,console