Ubuntu修改root密码

Ubuntu修改root密码的方法如下:

long@pc3:/usr/local/lib/python2.7/dist-packages$ sudo passwd
Enter new UNIX password:
Retype new UNIX password:
passwd: password updated successfully
long@pc3:/usr/local/lib/python2.7/dist-packages$ su - root
Password:
root@pc3:~# ls