Break/Reset Root Password

Resetting root password in CentOS/RHEL 7 is slightly different than the older versions. The post describes the procedure to reset the lost root password.

check my youtube video "Break Root Password" for your reference.

https://youtu.be/7FntXAYHrow

1. If your Linux system is currently running, reboot it. If it is not yet running, start it up. At the boot menu, press the ‘e’ key to edit the first boot entry.

2. When you are in edit mode, go to the line starting with linux16 and append rd.break to the end of this line.

This will cause the machine to boot into emergency mode, which gives you root user privileges without you having to enter a root user password. Even if the root user password hasn’t been set, this still works.

3. Press “Ctrl+x” to boot with these options. This will boot to the initramfs prompt with a root shell.

4. Remount sysroot and Reset root password.

First, we will remount the sysroot file system in read write mode and then use chroot to got into a chroot jail:

# mount -o remount ,rw /sysroot/

# chroot /sysroot/

Finally, type passwd command in the command line and set the new password for root user.

# passwd

Make sure that all unlabeled files ( including shadow file) gets relabeled during booting. Touching the hidden file autorelabel instructs SElinux to relabel the files changed outside of its regular context, like the file /etc/shadow.

# touch /.autorelable

Than exit command to leave the chroot environment and reboot the system.

# exit

# reboot