节点互信配置，

节点互信配置，

mkdir .ssh

chmod 700 .ssh

/usr/bin/ssh-keygen -t dsa

ssh rac2 cat .ssh/authorized_keys >> authorized_keys

scp authorized_keys rac1:.ssh/authorized_keys

这一块要对双节点全执行一遍
对自己也还要执行

$ssh rac1 date
$ssh rac1-priv date
$ssh rac2 date
$ssh rac2-priv date