1，停止所有Hadoop守护程序
for x in `cd /etc/init.d ; ls hadoop*` ; do sudo service $x stop ; done
2.从中删除所有文件
/var/lib/hadoop-hdfs/cache/hdfs/dfs/name
Eg: devan@Devan-PC:~$ sudo rm -r /var/lib/hadoop-hdfs/cache/
3，格式化Namenode
sudo -u hdfs hdfs namenode -format
4.启动所有Hadoop守护程序
for x in `cd /etc/init.d ; ls hadoop*` ; do sudo service $x start ; done
停止所有Hadoop服务
