生成密钥私钥
1、su hadoop
2、（在Hadoop01上）ssh-keygen -t rsa 三回车
3、查看 cd /home/hadoop/.ssh
4、在hadoop02与Hadoop03进行步骤1-3
5.（在hadoop02的hadoop）touch authorized_keys
6、（在hadoop01)
scp id_rsa.pub hadoop@192.168.20.112:/home/hadoop/.ssh/id_rsa.pub1
7、（在hadoop03）
scp id_rsa.pub hadoop@192.168.20.112:/home/hadoop/.ssh/id_rsa.pub3
8、（在hadoop02)
cat id_rsa.pub*>authorized_keys
9、（在hadoop02)
scp authorized_keys hadoop@192.168.20.111:/home/hadoop/.ssh/
scp authorized_keys hadoop@192.168.20.113:/home/hadoop/.ssh/
10.(三台）
su
vi /etc/selinux/config
11（三台root）
service iptables stop
12、（3台）
su hadoop
chmod 700 /home/hadoop/.ssh
chmod 600 /home/hadoop/.ssh/authorized_keys
13.测试是否成功
ssh 192.168.20.113
ifconfig
