This tutorial is going to show you a simple trick that you can use to reset your forgotten root password for CentOS 7 servers. Sometimes things happen and you totally forget your password. It happens to the best of us.
This tutorial will only work if you have direct access to the machine (example: You are next to the machine or have KVM/IPMI)
You can’t reset the root password if you’re remotely connected since you need boot menu access.
If you have a ServerHub Bare Metal Server this shouldn’t be an issue as we offer IPMI completely free with every server we sell.
To get started, turn on the machine that you’ve forgotten the root password on. For CentOS 7 devices, you’ll be given 5 seconds at the boot menu to select the operating system kernel to boot into.
That 5 seconds is important, because allows for admins to select different kernels or edit existing kernel parameters before booting.
At the boot menu, press e to edit the existing kernel (Core)
Next, scroll down to the list until you see the line underlined below (
Change the ro line to rw and add init=/sysroot/bin/sh
After changing that, press Control + X or Ctrl + X on your keyboard to start into single user mode using the bash shell specified above. In this mode, we’re going to change the root password.
In the single user mode, run the command as shown below
Finally, run the commands below to change the root password.
You’ll be prompted to create and confirm a new password. After creating the password, run the commands below to update SELinux parameters
Exit and reboot your system. Your password should now be successfully reset!