解决 Could not load host key: /etc/ssh/ssh_host_rsa_key 。。问题

问题： service ssh start
 * Starting OpenBSD Secure Shell server sshd                                                                                                                       Could not load host key: /etc/ssh/ssh_host_rsa_key
Could not load host key: /etc/ssh/ssh_host_dsa_key
Could not load host key: /etc/ssh/ssh_host_ecdsa_key

Could not load host key: /etc/ssh/ssh_host_ed25519_key

解决：sudo service ssh start
 * Starting OpenBSD Secure Shell server sshd