If you want to need passwordless SSH on Linux or Unix,you can do below steps.
rm -rf ./.ssh
chmod 700 .ssh
chmod go-w $HOME
ssh-keygen -t rsa
Generating public/private rsa key pair. Please be patient….
Key generation may take a few minutes Enter file in which to save the key (/oracle/.ssh/id_rsa):
Enter passphrase (empty for no passphrase):
Enter same passphrase again: Your identification has been saved in /oracle/.ssh/id_rsa.
Your public key has been saved in /oracle/.ssh/ .
The key fingerprint is: d6:2b:74:0e:56:51:db:56:f5:54:30:09:38:86:ec:a8
cat $HOME/.ssh/id_rsa.pub_server1 >> $HOME/.ssh/authorized_keys
cat $HOME/.ssh/id_rsa.pub_server2 >> $HOME/.ssh/authorized_keys