Symptom: "Permission denied (publickey)

[root@sachi ~]# mkdir /etc/ssh/gpadmin

[root@sachi ~]# cp /home/gpadmin/.ssh/authorized_keys /etc/ssh/gpadmin/

[root@sachi ~]# chown -R gpadmin:gpadmin /etc/ssh/gpadmin

[root@sachi ~]# chmod 755 /etc/ssh/gpadmin

[root@sachi ~]# chmod 644 /etc/ssh/gpadmin/authorized_keys

[root@sachi ~]# vi /etc/ssh/sshd_config 

#RSAAuthentication yes

#PubkeyAuthentication yes

# changed .ssh/authorized_keys to /etc/ssh/gpadmin/authorized_keys <<<<<<<

AuthorizedKeysFile      /etc/ssh/gpadmin/authorized_keys

#AuthorizedKeysCommand none

#AuthorizedKeysCommandRunAs nobody

Reboot the server