$ sbin/start-yarn.sh
$ cd ~/.ssh/ # 若没有该目录，请先执行一次ssh localhost
$ ssh-keygen -t rsa # 会有提示，都按回车就可以
$ cat id_rsa.pub >> authorized_keys # 加入授权
root@linuxidc.com:~# cd /usr/local/hadoop/
root@linuxidc.com:/usr/local/hadoop# sbin/start-all.sh
This script is Deprecated. Instead use start-dfs.sh and start-yarn.sh
Starting namenodes on [localhost]
localhost: starting namenode, logging to /usr/local/hadoop/logs/hadoop-root-namenode-linuxidc.com.out
localhost: starting datanode, logging to /usr/local/hadoop/logs/hadoop-root-datanode-linuxidc.com.out
........
5，启动验证
1）执行jps命令，有如下进程，说明Hadoop正常启动