RHEL 7.4 root password not working

[karthikmca.bhc]

Hi Erman,

Got one strange issue in production rhel 7.4 where oracle ebs application and database is running and I need your help to fix the issue asap.

I have changed RHEL 7.4 root user password 7 days before using in putty with the below command
#passwd root

It prompted for new password two times and It got successfully changed. So I assumed the new password has been set to root successfully and i closed the putty session.

Today when I am trying to connect to root with its new root password it is not logging in. I tried logging in with the old root password but that to not working and its denying to connect to root.

I am surprised what went wrong!. The way I changed the root password is correct or something I missed ?

Please help me how to fix this issue because it’s a production server.

Don't we have any solution for this other than resetting the root password at kernel level? Because i dont get downtime for production to perform the recovery by editing server kernel file for reset.

Your help is highly required here.

Regards,
Karthik

[ErmanArslansOracleBlog]

Please send me the screenshot of the error..

Normally, you change the root password by connecting with root and issuing passwd command.
Maybe someone else changed it once again, after you changed it..

In the worst case, you can reset it using the approach below;

Reboot and wait for the GRUB (bootloader) screen to appear
Highlight the kernel version you're currently using from the GRUB list
Press "e" to be taken to the boot commands edit screen, highlight the line which starts with kernel and press "e" again
Add "single" to the end of the line -> kernel /vmlinuz-kernel-version ro root=LABEL=/ rhgb quiet single
Press "Enter" (save the changes)
Press "b" to boot in single user mode

You will find yourself in a root shell where you can change the password of the root using passwd command.

While setting the root password, ensure you are aligned with the password policy of yours (if you have one ofcourse)