DISCLAIMER: this is not my post is only a copy, in case the original get deleted or whatever, posting on my personal blog get easier for me to find it. You can find the original one in this link https://vpsie.com/knowledge-base/boot-single-user-mode-centos-rhel-vpsie/
The first thing to do is to open Terminal and log in to you CentOS 7 server.
After, restart your server wait for GRUB boot menu to show.
Next step is to select your Kernel version and press
e
key to edit the first boot option.Find the kernel line (starts with “linux16“), then change the
ro
to
rw init=/sysroot/bin/sh .
When you have finished, press
Ctrl-X
or
F10
to boot into single user mode
After mount root filesystem using the following command:
chroot /sysroot/
Now, to finish this process reboot your server using the following command:
reboot -f