1. sudo chmod u+w /etc/sudoers
    1. sudo vi /etc/sudoers
    2. 找到：
    3. # root and users in group wheel can run anything on any machine as any user
    4. root        ALL = (ALL) ALL
    5. %admin      ALL = (ALL) ALL
    7. 修改为：
    8. # root and users in group wheel can run anything on any machine as any user
    9. #root       ALL = (ALL) ALL
    10. #%admin     ALL = (ALL) ALL
    11. root            ALL = (ALL) NOPASSWD: NOPASSWD: ALL
    12. %admin          ALL = (ALL) NOPASSWD: NOPASSWD: ALL