配置SSH免密码登录：
需要先关闭selinux，否则会互信失败
[root@rhel-1 ~]# ssh-keygen -t rsa Generating public/private rsa key pair. Enter file in which to save the key (/root/.ssh/id_rsa): Created directory '/root/.ssh'. Enter passphrase (empty for no passphrase): Enter same passphrase again: Your identification has been saved in /root/.ssh/id_rsa. Your public key has been saved in /root/.ssh/id_rsa.pub. The key fingerprint is: 95:77:9d:9b:1d:43:5d:19:32:f2:7e:ad:97:f5:56:be root@rhel-1 [root@rhel-1 ~]#
此时还需要输入密码
[root@rhel-1 ~]# scp .ssh/id_rsa.pub root@192.168.100.249:/root
[root@rhel-2 ~]# cat id_rsa.pub >> .ssh/authorized_keys
[root@rhel-2 ~]# chmod 600 .ssh/authorized_keys
[root@rhel-1 ~]# ssh 192.168.100.249 Last login: Fri Jun 12 09:27:00 2015 from 192.168.100.251 [root@rhel-2 ~]#
