Shulou(Shulou.com)06/01 Report--

Today, I encountered a problem when I was testing my virtual machine. Login to centos has always returned login, the account number and password are correct, I have also changed two users.

1. Problem description

I enter my user name and password normally.

Error screenshot: back to the login screen, I retried another oracle user and found that the same returned login

two。 Error analysis

I made a mistake at Baidu and later found an article about this problem, http://blog.itpub.net/35489/viewspace-620915/, because I just installed oracle with my virtual machine yesterday.

I found the reason because I modified the / etc/pam.d/login file when I installed oracle yesterday. Later, I found out that there was something wrong with the sentence I added.

It turns out that there is something wrong with my statement restriction sentence:

# session required / lib64/security/pam_limits.so, which corresponds to 64-bit

Session required / lib/security/pam_limits.so this corresponds to 32-bit. The reason I have a problem is that I am using 32-bit statements and I am a 64-bit system.

3. Solution method

I checked for a long time and almost reinstalled the system, and then I found two solutions.

I checked the information http://blog.itpub.net/15480802/viewspace-1406088/ on the Internet and found that pam_securetty.so read / etc/securrety, set the terminal that root users can log in, generally only set tty but not pts/0,telnet to use this module, so can not use root users to log in, but sshd does not use this module so there is no restriction

Through this analysis and data search, I have found two solutions.

a)。 Ssh crt can be connected to the computer, and know the ip

Connect the system remotely through the software of the ssh crt class, and then change the file vi / etc/pam.d/login to change session required / lib/security/pam_limits.so to session required / lib64/security/pam_limits.so

(screenshot of 1:crt connection is attached. I wouldn't do it when I first worked. No one told me, I wouldn't be embarrassed to ask, and even the people around me refused to tell me seriously.

(attachment 2: press the keyboard I to enter the text mode after the operation of the vim editor is entered, otherwise it cannot be edited in command mode. Exit text mode is esc (key) and then press: (symbol, shif +;: key on the keyboard) and then save is input wq, if you do not save is Q!. This is simple, but it's embarrassing if I don't know. I was reprimanded and laughed at by my colleagues when I first came into contact with this at work. As long as you put your heart into it. )

As shown in the picture

The second method: for those who do not surf the Internet and cannot connect to SSH crt software

This method is rather stupid, which is to restart the system and enter the linux mode. How to enter the single mode system http://jingyan.baidu.com/article/7e440953f87f4a2fc0e2ef90.html

This method can also be applied to retrieve passwords. But this time this entry but mode reset password doesn't work, at least I tried to reset the password.

After entering single mode, directly change the file vi / etc/pam.d/login, changing session required / lib/security/pam_limits.so to session required / lib64/security/pam_limits.so

Attachment 3: how to enter single mode brief introduction: restart the system, and then in the login interface, press the keyboard e to enter the following figure

Select the second kernel, then type 1 or single and enter, then press b to wait to enter single-user mode, and modify in this mode.

4. Log in again and you can use it normally.

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