集群搭建-ssh免密登录

免密码ssh

• 在搭建hadoop集群时，需要机器相互可以免密码ssh，操作如下（所有机器都要操作）：

  # ssh-keygen -t rsa

• 将产生的公钥复制到第一台机器
  # scp ~/.ssh/id_rsa.pub root@host:~/id_rsa.pub.1
• 将所有密钥追加到authorized_keys中：
  # cat ~/.ssh/id_rsa.pub >> ~/.ssh/authorized_keys
# cat ~/id_rsa.pub.1 >> ~/.ssh/authorized_keys
# cat ~/id_rsa.pub.2 >> ~/.ssh/authorized_keys
# cat ~/id_rsa.pub.3 >> ~/.ssh/authorized_keys
  …
• 修改authorized_keys权限
  # chmod 700 ~/.ssh
# chmod 600 ~/.ssh/authorized_keys
• 分发到集群的各个机器：
  # scp ~/.ssh/authorized_keys root@host1:~/.ssh/authorized_keys
# scp ~/.ssh/authorized_keys root@host2:~/.ssh/authorized_keys
# scp ~/.ssh/authorized_keys root@host3:~/.ssh/authorized_keys