As a Linux administrator, you may need to troubleshoot certain instances and fix boot issues. This is usually achieved by booting the system into emergency / recovery mode from the Grub menu. In this guide, you will learn to diagnose problems and recover the system from emergency mode.

Boot CentOS / RHEL 7 & 8 Linux into Emergency / Recovery Mode

Power on your RHEL / CentOS 7/8 LInux machine. When the bootloader menu appears, press Enter Interrupt countdown.

press Ë Key to edit the current entry so that we can modify the default boot loader entry and log into emergency mode.

Now use the cursor keys to navigate to linux . You need to attach systemd.unit=emergency.target To the end of the line

press Ctrl + X Key to start with the modified configuration.

Login to Emergency situations Enter the mode by entering the root password.

Reinstall using mount command / File system read / write. This will enable you to edit the file system.

                      
                        # mount -o remount,rw /
                      
                    

You should be able to rescue a failed system from emergency mode. See more Linux guides below.

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• Boot CentOS 8 / CentOS 7 to Recovery Mode
• Boot CentOS 8 / CentOS 7 into emergency mode
• Start CentOS 8 / CentOS 7 in single user mode
• Boot RHEL 8 / RHEL 7 into single-user mode
• Boot RHEL 8 / RHEL 7 into Recovery Mode
• Boot RHEL 8 / RHEL 7 into emergency mode