[root@centos7 ~]$ hostnamectl set-hostname hadoop001 # 使用这个命令会立即生效且重启也生效
[root@centos7 ~]$ hostname # 查看下
hadoop001
[root@centos7 ~]$ vim /etc/hosts # 编辑下hosts文件， 给127.0.0.1添加hostname
[root@centos7 ~]$ cat /etc/hosts # 检查
127.0.0.1 localhost localhost.localdomain localhost4 localhost4.localdomain4 hadoop001
::1 localhost localhost.localdomain localhost6 localhost6.localdomain6

scp id_rsa.pub lau@192.168.1.108:/home/lau/.ssh/pub_key
#登录用户
cd ~/.ssh/
cat pub_key >> authorized_keys
chmod 600 /home/lau/.ssh/authorized_keys