hadoop免密登陆:
生成秘钥:
ssh-keygen -t dsa -P ‘‘ -f ~/.ssh/id_dsa
cat ~/.ssh/id_dsa.pub >> ~/.ssh/authorized_keys
cat ~/id_dsa.pub >> ~/.ssh/authorized_keys
scp id_dsa.pub root@192.168.80.102:~
/etc/hosts，主机名和IP配置文件: vi /etc/hosts回车,切换到编辑模式‘i‘,手动添加
127.0.0.1 node1 localhost
192.168.80.102 node2
192.168.80.103 node3
192.168.80.104 node4
::1 localhost6.localdomain6 localhost6
~
day02 秘钥生成,免密访问命令
原文：http://www.cnblogs.com/duenboa/p/6665427.html
