Red Hat enterprise Linux v5-Keeps prompting for username & password while loggin in
 

Hi,

I was trying to log into root but the username prompts keeps coming back after I typed in the password. It was not an incorrect password but it's going to expire in 3 days.

When I tried to change the root password, I get a "Module is unknown" message.

Anyone knows how I can get logged in?

I have went through with the red hat support but in vain. I can only remember we checked the following:

/etc/pam.d/system-auth
/etc/passwd
/etc/shadow
/etc/security/opasswd
/root/.bash_profile
/etc/pam.d/system-auth
check Selinux status


As I am quite new to Linux, I have been going through the thread but failed to find any possible solution to this issue.

I would really appreciate if anyone here can provide some help. Thanks in advance.

Try re-booting into single-user mode:
Reboot
When the grub menu appears, hit any key to stop the count
Select the desired OS to boot, and hit "e" for edit.
Select the kernel line and "e" again
At the end of the kernel line, add "single" (no quotes)
Enter and then "b" to boot.

It should come up in a root terminal with no password required. You can then enter a new password using "passwd root"

Hi Pixellany,

Thanks for the quick response, but I was still unable to change any password or log into linux.

I was able to boot into single user mode, but the same error about unknown module still appears when I tried to change the root password.

The problem was it immediately went back to prompt me for username and password after I have keyed the password.
The red hat support staff went through with me and verify that my password is expiring but still can use. I just dun know why it cannot get authenticated to log in. :(

Any further suggestion is appreciated. Thanks.

Can I use a rescue disk to change the root password? I heard we can do that but I have also consulted the red hat support ppl, and the support staff doesn't recommend it but he couldn't tell me his concerns.
He say that the installation disk is supposed to be used only for irreversible changes to system.

Can anyone give me a second opinion? Any comment is appreciated. Thanks.

I'm puzzled about the "unknown module". Are those the exact words?

If I enter a nonsense word in a bash terminal, I get: "command not found"

Hi,

The exact words is "Module is Unknown"

I have a feeling that the password file or something is corrupted or something like that.
Somehow, the authentication process was not processed or have errors, and the system just return me back to the log in screen.

Below is a representation of the screen during log in attempts under normal condition -

notes2_nt login: root
Password: XXXXXXXXX

the next moment, it shows:
notes2_nt login: _

==================================================================================================== ======================================

I had some assistance from someone and we use the command "cat /etc/passwd" and "more /etc/passwd" to check any existing users and tried to use them, but I do not have the passwords. When I use a wrong password, the system will return an error message saying "Login Incorrect"

Below are 2 representations of the screen during my attempts to change passwords.

E.g 1 - Changing the root password
sh-3.1# passwd root
Changing password for user root.
passwd: Module is unknown
sh-3.1#

[U]E.g 2 - Changing another username password; username: notes
sh-3.1# passwd notes
Changing password for user notes.
passwd: Module is unknown
sh-3.1#

Description to the above examples:
It doesn't allow me to change any password even under the shell prompt.

Do let me know if there is anything I could do or any further checks I should take to isolate the problem. Thanks a million guys.

1. If it says 'module is unknown' I'd expect it to mean that a pam module that is being called doesn't exists, or there is a typo in the module name being called.
Also check the ownerships/perms for all the pam modules.

2. you can reboot the server from the install media; at the initial prompt enter

linux rescue

and follow the prompts.

Prob best to clear the root passwd. Ensure you create an admin user in sudoers file with ALL privs, so you can work on the problem.
Do other userids have this issue or only root?

Hi Chris,

This is a Notes server so no users will come here to log into the OS. I've tried using the single user mode to change another username account's password. Same problem occurred.. It says, 'Module is unknown' :S

Thanks for the tip. I guessed I will have to check out your suggestion later.. cos now I am having a new problem as I can't get the CDROM drive to boot from the install disk.. :( It seem to always bypass the CDROM drive (even though I have ensure that CDROM is the first boot device in the BIOS) and goes directly to boot from the OS itself.

Let you guys knows if I am successful after I managed to get it boot from the CDROM. Thanks guys. Really appreciate all the help here.. :)

Regards,

Cher Kian, Teo

Just double check the install media by booting another system from it...

Not sure if this was solved or not, but I found this thread through Google when having a similar problem with logging in.

I was able to solve it with the steps outlined here, in case anyone else comes across this thread with a similar problem.