RHEL5: SCP,SSH 不输入密码的方法

1. Setup a new directory ".ssh" under the home folder:  
$ mkdir .ssh

2. Set the priority of ".ssh" as drwxr-xr-x:  
$ chmod 755 .ssh

3. Generating public key of the namenode for passphraseless SSH  
$ ssh-keygen -t rsa  
$ ssh-keygen -t dsa  
and press three "Enter"s

4. Add the public key SSH to authorized key list:  
If "~/.ssh/authorized_keys" does not exit:  
$ cp ~/.ssh/id_rsa.pub ~/.ssh/authorized_keys  
Else appending:  
$ cat ~/.ssh/id_rsa.pub >> ~/.ssh/authorized_keys  
$ cat ~/.ssh/id_dsa.pub >> ~/.ssh/authorized_keys