{"id":6851,"date":"2017-01-09T14:50:46","date_gmt":"2017-01-09T06:50:46","guid":{"rendered":"https:\/\/webhostinggeeks.com\/howto\/?p=6851"},"modified":"2023-04-28T09:47:04","modified_gmt":"2023-04-28T09:47:04","slug":"reset-forgotten-root-password-on-linux","status":"publish","type":"post","link":"https:\/\/webhostinggeeks.com\/howto\/reset-forgotten-root-password-on-linux\/","title":{"rendered":"How to Reset Forgotten Root Password on Linux RHEL 7 \/ CentOS 7"},"content":{"rendered":"

\"Reset<\/p>\n

This short howto will explain the steps to reset a lost root password or to reset a forgotten root password on Linux RHEL 7 or CentOS 7.<\/p>\n

Basically, we will add a “rd.break<\/strong>” to the end of the line with kernel parameters in Grub to stop the start-up process before the regular root filesystem is mounted, hence the necessity to chroot into sysroot.<\/p>\n

This will allow you to break into your Linux system and reset the root password back to your own.<\/p>\n

Please note that in below steps, you will use “rd.break<\/strong>” instead of alternative method “init=\/bin\/sh<\/a><\/strong>” to recover your lost root password.<\/p>\n

Steps to Reset Forgotten Root Password on Linux RHEL 7\/CentOS 7<\/h2>\n

1. Reboot your system and interrupt the countdown in the boot loader menu.<\/p>\n

In order to interrupt the countdown, you need to press any key when the boot loader menu appears.<\/p>\n

2. Edit the default boot loader entry to abort the boot process just after all file systems have been mounted, but before control is handed over to systemd, then boot.<\/p>\n

Use the cursor keys to highlight the default boot loader entry. On the GRUB 2 boot screen, press e to edit the current entry.<\/p>\n

\"Reset<\/p>\n

3. Using the cursor keys, navigate to the line that starts with linux16<\/strong> if you are using on x86-64 BIOS-based systems and navigate to the line that starts with Linux line on 64-Bit IBM Power Series.<\/p>\n

Press End to move the cursor to the end of the line.<\/p>\n

\"recover<\/p>\n

4. Append “rd.break<\/strong>” or “rd.break enforcing=0<\/strong>” to the end of the line. Both gives the same result.<\/p>\n

# rd.break\r\n<\/pre>\n
or<\/p>\n
# rd.break enforcing=0\r\n<\/pre>\n
Use option “rd.break<\/strong>”<\/p>\n
\"recover<\/p>\n
Use option “rd.break enforcing=0<\/strong>”<\/p>\n
\"Reset<\/p>\n
Note<\/strong>: Adding enforcing=0<\/strong> puts the system into SELinux Permissive mode. This option enables omitting the time-consuming SELinux relabeling process and allows you to complete the boot process despite having mislabeled files.<\/p>\n
5. Press Ctrl+x<\/strong> to boot using the modified config.<\/p>\n
6. The file system is mounted read-only on \/sysroot\/. You will not be allowed to change the password if the file system is not writable. Run the following command to remount the root filesystem in read-write mode:<\/p>\n
# mount -oremount,rw \/sysroot\r\n<\/pre>\n
7. Then use chroot to go into a chroot jail at \/<\/strong>sysroot. Change the file system’s root as follows:<\/p>\n
# chroot \/sysroot\r\n<\/pre>\n
8. Change the root password to your own password.<\/p>\n
# passwd root\r\n<\/pre>\n
9. Configure the system to automatically perform a full SELinux relabel after boot. This is necessary since the passwd tool re-created the \/etc\/shadow file without an SELinux context.<\/p>\n
# touch \/ .autorelabel\r\n<\/pre>\n
10. Type exit twice to continue booting your system as normal. The system will run an SELinux relabel, then reboot again by itself.<\/p>\n
\"Reset<\/p>\n
I hope this article gives you some ideas and essential guidance on how to reset forgotten root passwords on Linux RHEL 7 and CentOS 7.<\/p>\n
Resources:<\/strong><\/p>\n