[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

:: 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  /home/lau/.ssh/authorized_keys