How To Properly Change Username In Linux

This brief guide explains how to properly change username in Linux operating system. Not just the username, this guide also describes how to change the hostname, user group, home directory and the ownership and group of that directory to the new user, along with all files.

Introduction

A few days ago, I downloaded a Fedora vagrant box and deployed it using libvirt/kvm provider. As you might already know, all vagrant boxes comes with a default user called "vagrant". And the default hostname for the vagrant box is localhost. I changed the username and hostname in the Fedora VM for better accessibility in the network.

If you're ever looking for a proper way to change the username in Linux without messing the existing configuration files, here is how.

The right way to change username in Linux

Changing hostname in Fedora and other Linux distributions is easy!

Login as a different sudo user or root user. Because you can't change the username of the currently logged in user. I logged in as root user.

Change the current hostname using the hostnamectl command like below:

# hostnamectl set-hostname fedora33

The above command changes the old hostname to "fedora33". Log out and log back in to apply the changes. You will now see that the hostname is updated in the shell prompt. You can also check it using hostname command:

# hostname
fedora33

Here comes the main part. Now I am going to change the user name from "vagrant" to "ostechnix". To do so, I created a new group called "ostechnix" using command:

# groupadd ostechnix

For the purpose of this guide, I used the same name for user and group. You can use different name if you want.

And finally change the username using the usermod command like below:

# usermod -d /home/ostechnix -m -g ostechnix -l ostechnix vagrant

Let us break down the above command and see what each option does.

• usermod : The command to modify a user account in Unix-like systems.
• -d /home/ostechnix : Create a new $HOME directory for the user.
• -m : Move the content of the old user's $HOME directory to the new location.
• -g ostechnix : Add the new user to a group called "ostechnix".
• -l ostechnix vagrant : Change the name of the user from "vagrant" to "ostechnix". i.e. "vagrant" is the old user name and "ostechnix" is the new user.

The above command changes the user name, the user group, the $HOME directory and ownership and group of that directory to the new user, along with all the user's files and directories.

Finally, assign sudo privileges to the new user using command:

# usermod -aG wheel ostechnix

If you're on Debian-based systems like Ubuntu, you can grant sudo permissions to the user using this command:

$ sudo usermod -aG sudo ostechnix

Now exit from the root user and log in as new user.

Verify if the hostname, username, and $HOME directories are changed:

Great! Everything is changed.

For more details about usermod command, refer its man page:

$ man usermod

Hope it helps.