[root@centos7 ~]$ hostnamectl set-hostname hadoop001 # 使用這個命令會立即生效且重啟也生效
[root@centos7 ~]$ hostname # 查看下
hadoop001
[root@centos7 ~]$ vim /etc/hosts # 編輯下hosts文件， 給127.0.0.1添加hostname
[root@centos7 ~]$ cat /etc/hosts # 檢查
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
#登錄用戶
cd ~/.ssh/
cat pub_key >> authorized_keys
chmod 600 /home/lau/.ssh/authorized_keys