LKBEN10996: Howto change your root password after you forgot it


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LKB | Created: 02/04/2020 | Version: 0 | Language: EN | Rating: 0 | Outdated: False | Marked for deletion: False

Author: Wim Peeters - Keskon GmbH & Co. KG


Symptom

You forgot your root password and need to get into the system

Cause

You should not forget your root password!

Solution

When you forget your root password, you need at least physical access to the server or system. You have to make it possible to boot into single user mode which depends on your bootloader. You can search in the lubby database to find some entries.

After you started in single user mode you can change the password with the passwd command. 

When the boot loader grub or lilo are password protected you need a few more tricks.  You need at least a rescue disk. (a CD / DVD) After you started you need to mount the disks of the system and chroot into them.

chroot /mnt/mydisk

This assumes you mounted your root disk on /mnt/mydisk. Now you can change your password with the passwd command again. 

About the Author

Wim Peeters is electronics engineer with an additional master in IT and over 30 years of experience including time spent in support, development, consulting, training and database administration. Wim has worked with SQL Server since version 6.5. He has developed in C/C++, Java and C# on Windows and Linux in different European countries and different European languages. He writes knowledge base articles to solve IT problems and publishes them on the Lubby Knowledge Platform where he is one of the most important contributors and the main developer.

Disclaimer:

The information provided in this document is intended for your information only. Lubby makes no claims to the validity of this information. Use of this information is at own risk!