As a Linux Administrator, there are instances you may want to troubleshoot and repair boot problems. This is often achieved by booting the system into emergency / recovery mode from the Grub menu. In this guide, you will learn to diagnose issues and recover the system from emergency mode.
Booting CentOS/RHEL 7&8 Linux into Emergency / Recovery mode
Start your RHEL / CentOS 7/8 LInux machine. When the boot-loader menu appears, press any key except Enter to interrupt the countdown.
Press e key to edit the current entry so we can modify the default boot-loader entry and log in to emergency mode.
Now use the cursor keys to navigate to the line that starts withlinux
. You need to appendsystemd.unit=emergency.target
to the end of the line.
Press Ctrl x key to boot using the modified configuration.
Log in to emergency mode by entering the root password.
Use the mount command to remount the / file system read/write. This will enable you to edit the file system.
# mount -o remount,rw /
You should be able to rescue a broken system from the emergency mode. See more Linux guides below.
Tags:
- Boot CentOS 8 / CentOS 7 in to recovery mode
- Boot CentOS 8 / CentOS 7 in to emergency mode
- Boot CentOS 8 / CentOS 7 in to single user mode
- Boot RHEL 8 / RHEL 7 in to single user mode
- Boot RHEL 8 / RHEL 7 in to recovery mode
- Boot RHEL 8 / RHEL 7 in to emergency mode