1）停止Hadoop集群

2）确保所有的服务器上zkServer都在运行

[user@NewBieSlave2 ~]$ zkServer.sh start
ZooKeeper JMX enabled by default
Using config: /home/user/apache-zookeeper/bin/../conf/zoo.cfg
Starting zookeeper ... STARTED
[user@NewBieSlave2 ~]$ zkServer.sh status
ZooKeeper JMX enabled by default
Using config: /home/user/apache-zookeeper/bin/../conf/zoo.cfg
Client port found: 2181. Client address: localhost. Client SSL: false.
Mode: follower
[user@NewBieSlave2 ~]$ 

3）在Hadoop的主服务器66上执行格式化命令行

hadoop namenode -format