ubuntu - sudo: 3 incorrect password attempts

Question

今天大多时候用的好好的，突然就出现了
sudo: 3 incorrect password attempts

详情如下：

~$ sudo -i
Sorry, try again.
Sorry, try again.
Sorry, try again.
sudo: 3 incorrect password attempts

希望高手能指点一下这是什么原因导致或者告知一下诊断的方法。

补充：
http://unix.stackexchange.com/questions/9218/why-does-my-sudo-ask-for-password-only-once-but-evaluate-thrice

链接的页面和我遇到的情况很相似，也有人进行了重现和深入的解答，但是我的英语水平和对linux理解有限，没看明白说的是什么，希望看懂的人能高速我一下。

Answer 1

Did your arm hit the keyboard?

http://serverfault.com/questions/543888/sudo-does-not-prompt-for-password-and-reports-3-incorrect-password-attempts

Answer 2

The prompt indicates that the password was entered incorrectly

Answer 3

I have also encountered this problem and I don’t know how to solve it yet

I have solved it.

Solution:

You need to find a quick machine

Check the file contents in the /etc/pam.d/ folder.

Usually the system-auth-ac or system-auth configuration is unreasonable;

After modification ok

Clear the number of incorrect inputs by your user
Use the command pam_tally2

Study the specific usage yourself