# ssh-keygen -f /root/.ssh/id_rsa_cluster
Generating public/private rsa key pair.
Created directory '/root/.ssh'.
Enter passphrase (empty for no passphrase): 
Enter same passphrase again: 
Your identification has been saved in /root/.ssh/id_rsa_cluster.
Your public key has been saved in /root/.ssh/id_rsa_cluster.pub.
The key fingerprint is:
bb:0f:e3:7f:3e:ab:c3:5d:32:78:85:04:a2:da:f1:61 root@host1