搭建Hadoop完全分布式集群

ssh-copy-id -i ~/.ssh/id_rsa.pub 用户名@对方机器IP (注意不要忘记了参数-i)

注：ssh-copy-id -i 是最简单的办法，如果不用这个，就得分二个步骤:
https://www.cnblogs.com/zhijianliutang/p/5756738.html
https://www.cnblogs.com/qingyunzong/p/8496127.html