1.启动前先将主节点下hadoop-2.2.0/hdfs/下,清空,然后新建name文件夹 2.将从节点下hadoop-2.2.0/hdfs/下,清空,然后新建data文件夹 3.hadoop-2.2.0/下,文件系统格式化,bin/hadoop namenode -format 4.启动hdfs与yarn: 进入目录sbin下,./start-dfs.sh(可进入50070端口查看),./start-yarn.sh(可进入8088端口查看) 5.运行pi实例:bin/hadoop jar ./