hadoop软件包常见目录说明
bin:hadoop客户端名单
etc/hadoop:hadoop相当的配置文件粗存放目录
sbin: 启动Hadoop相关进程的脚本
share：常用列子

注意：
start/stop-dfs.sh与hadoop-daemons.sh的关系
start-dfs.sh = hadoop-daemons.sh start namenode
hadoop-daemons.sh start datanode
hadoop-daemons.sh start secondarynamenode

stop-dfs.sh = 

[root@hadoop000 sbin]# ./stop-dfs.sh 

[root@hadoop000 sbin]# ./hadoop-daemons.sh start namenode

[root@hadoop000 sbin]# ./hadoop-daemons.sh start datanode
[root@hadoop000 sbin]# ./hadoop-daemons.sh start secondarynamenode