默认情况下，禁用到Ubuntu 14.04 Linux服务器的root ssh登录。这是一项安全功能，即使您更改root密码，root ssh登录也将被拒绝，显示类似以下内容的消息：
$ ssh This email address is being protected from spambots. You need JavaScript enabled to view it.
document.getElementById('cloake01ba6f0754bcc5af1b11082fe0e068a').innerHTML='';var prefix='ma'+'il'+'to';var path='hr'+'ef'+'=';var addye01ba6f0754bcc5af1b11082fe0e068a='root'+'@';addye01ba6f0754bcc5af1b11082fe0e068a=addye01ba6f0754bcc5af1b11082fe0e068a+'10'+'.'+'1'+'.'+'1'+'.'+'12';var addy_texte01ba6f0754bcc5af1b11082fe0e068a='root'+'@'+'10'+'.'+'1'+'.'+'1'+'.'+'12';document.getElementById('cloake01ba6f0754bcc5af1b11082fe0e068a').innerHTML+=''+addy_texte01ba6f0754bcc5af1b11082fe0e068a+'';
This email address is being protected from spambots. You need JavaScript enabled to view it.document.getElementById('cloak39d21dce0a2f7ab55a5c3a5ac15611b9').innerHTML='';var prefix='ma'+'il'+'to';var path='hr'+'ef'+'=';var addy39d21dce0a2f7ab55a5c3a5ac15611b9='root'+'@';addy39d21dce0a2f7ab55a5c3a5ac15611b9=addy39d21dce0a2f7ab55a5c3a5ac15611b9+'10'+'.'+'1'+'.'+'1'+'.'+'12';var addy_text39d21dce0a2f7ab55a5c3a5ac15611b9='root'+'@'+'10'+'.'+'1'+'.'+'1'+'.'+'12';document.getElementById('cloak39d21dce0a2f7ab55a5c3a5ac15611b9').innerHTML+=''+addy_text39d21dce0a2f7ab55a5c3a5ac15611b9+'';'s password:
Permission denied, please try again.
This email address is being protected from spambots. You need JavaScript enabled to view it.document.getElementById('cloak68265cd6972327ac3876750edf860cab').innerHTML='';var prefix='ma'+'il'+'to';var path='hr'+'ef'+'=';var addy68265cd6972327ac3876750edf860cab='root'+'@';addy68265cd6972327ac3876750edf860cab=addy68265cd6972327ac3876750edf860cab+'10'+'.'+'1'+'.'+'1'+'.'+'12';var addy_text68265cd6972327ac3876750edf860cab='root'+'@'+'10'+'.'+'1'+'.'+'1'+'.'+'12';document.getElementById('cloak68265cd6972327ac3876750edf860cab').innerHTML+=''+addy_text68265cd6972327ac3876750edf860cab+'';'s password:
Permission denied, please try again.
This email address is being protected from spambots. You need JavaScript enabled to view it.document.getElementById('cloak710413d5b0db45bc1be051b9b689ec6f').innerHTML='';var prefix='ma'+'il'+'to';var path='hr'+'ef'+'=';var addy710413d5b0db45bc1be051b9b689ec6f='root'+'@';addy710413d5b0db45bc1be051b9b689ec6f=addy710413d5b0db45bc1be051b9b689ec6f+'10'+'.'+'1'+'.'+'1'+'.'+'12';var addy_text710413d5b0db45bc1be051b9b689ec6f='root'+'@'+'10'+'.'+'1'+'.'+'1'+'.'+'12';document.getElementById('cloak710413d5b0db45bc1be051b9b689ec6f').innerHTML+=''+addy_text710413d5b0db45bc1be051b9b689ec6f+'';'s password:
Permission denied (publickey,password).
为了允许在Ubuntu 14.01 Linux服务器/桌面上进行root SSH登录，sshd守护程序的配置文件/etc/ssh/sshd_config需要改变。打开/etc/ssh/sshd_config并对以下指定的行进行以下更改：
FROM:
PermitRootLogin without-password
TO:
PermitRootLogin yes
进行更改后，请重新启动SSHD服务，以使这些更改生效：
# service ssh restart
ssh stop/waiting
ssh start/running, process 6919
完成后，您可以SSH登录到ubuntu服务器：
$ ssh This email address is being protected from spambots. You need JavaScript enabled to view it.document.getElementById('cloak12fd743a3b860378f365089055bdd175').innerHTML='';var prefix='ma'+'il'+'to';var path='hr'+'ef'+'=';var addy12fd743a3b860378f365089055bdd175='root'+'@';addy12fd743a3b860378f365089055bdd175=addy12fd743a3b860378f365089055bdd175+'10'+'.'+'1'+'.'+'1'+'.'+'12';var addy_text12fd743a3b860378f365089055bdd175='root'+'@'+'10'+'.'+'1'+'.'+'1'+'.'+'12';document.getElementById('cloak12fd743a3b860378f365089055bdd175').innerHTML+=''+addy_text12fd743a3b860378f365089055bdd175+'';
This email address is being protected from spambots. You need JavaScript enabled to view it.document.getElementById('cloakf985e3fa77aaca8a49fe645e03f0cbf5').innerHTML='';var prefix='ma'+'il'+'to';var path='hr'+'ef'+'=';var addyf985e3fa77aaca8a49fe645e03f0cbf5='root'+'@';addyf985e3fa77aaca8a49fe645e03f0cbf5=addyf985e3fa77aaca8a49fe645e03f0cbf5+'10'+'.'+'1'+'.'+'1'+'.'+'12';var addy_textf985e3fa77aaca8a49fe645e03f0cbf5='root'+'@'+'10'+'.'+'1'+'.'+'1'+'.'+'12';document.getElementById('cloakf985e3fa77aaca8a49fe645e03f0cbf5').innerHTML+=''+addy_textf985e3fa77aaca8a49fe645e03f0cbf5+'';'s password:
Welcome to Ubuntu 14.04 LTS (GNU/Linux 3.13.0-24-generic x86_64)