RHCSA

Reset Root Password

GRUB menu PRESS e
Navigate to a line starts with 'linux' and press CTRL + e (the end of the line)
Append the following at the end of the line: init=/bin/bash
PRESS CTRL + x
- grep "/" /proc/mounts --> to check ro (look at /) The filesystem will usually be mounted as read-only
mount -o remount,rw / --> remount as read-write:
- grep "/" /proc/mounts --> to recheck ro change to rw
- echo $PATH
- /sbin/getenforce --> check SELinux disable
ls -lZ /etc/shadow --> CRITICAL to refer "system_u:object_r:shadow_t:s0" before set root password
passwd --> to set a root password
chcon system_u:object_r:shadow_t:s0 /etc/shadow --> to Change Context shadow file as before
- ls -lZ /etc/shadow --> to recheck
exec /sbin/init --> to reboot the system!

Resources

Book

RHCSA Red Hat Enterprise Linux 9: Training and Exam Preparation Guide (EX200), Third Edition by Ghori, Asghar
Red Hat Rhcsa 9 Cert Guide: Ex200 By Van Vugt, Sander

Video

RHCSA® RHEL 9 Complete Video Course By Van Vugt, Sander

Youtube