Login as single user mode on CentOS 8
1. boot on GRUB Menu 2. add argument rd.break behind as follow: Linux .... rhgb quit rd.break 3. press Ctrl+x for booting 4. mount sysroot as follow mount -o remount,rw /sysroot chroot /sysroot 5. check identification as follow bin/sh# whoami 6. If you want to modify root password /bin/sh# passwd if you want to fix sudo suid problem(error message: sudo : /usr/bin/ sudo must be owned by uid 0 and have the setuid bit set) , you can use instruction as follow /bin/sh# chmod u+s /usr/bin/sudo 7. Important!!! #relabel SELinux protected files /bin/sh# touch / .autorelabel 8. Rebooting machine /bin/sh# reboot -f Reference https://www.linuxtechi.com/boot-centos-8-rhel-8-single-user-mode/ https://www.itzgeek.com/how-tos/linux/centos-how-tos/how-to-boot-into-single-user-mode-in-rhel-8.html