Let this practical guide help you create users and groups & add them to groups in CentOS7 with ease.

1. Your Practical Guide to
Creating Users and Groups
in CentOS7
Linux, an operating system that has been around for quite some
time, still amazes many users. Despite having a few similarities
in capabilities, strength, and robustness with popular Operating
Systems, Linux has carved a niche for itself.
You may be well acquainted with managing the basic tasks, but
some avenues require you to be absolutely sure before you
perform them. Dealing with CentOS is one of them.
A brief about CentOS:
CentOS, by nature, is a free and popular operating system.
Besides being community-driven, CentOS is an open-source
Linux Distribution having its roots in the Red Hat Enterprise
Linux source code. Built fundamentally on the core Linux kernel,
CentOS is a highly stable Operating System offering enormous
security and has developed a niche class of users for itself.
Note: Before beginning your journey, you must either log in as a
“Root User” or a “non-root sudo-enabled user.” For ease of
explanation, we have used the Root User.
Sudo means "substitute user do" or "super user do." If you log in
using a sudo-enabled user, you must add the word “sudo” at
the beginning of each command.
Also Read: How To Install CentOS Web Panel In CentOS

2. Add or Create a User in CentOS:
a. Log in as a root user to your server
Command: ssh root@server_ip_address
b. For adding a new user, type the command adduser in the
system.
Caution: Username indicates the user that you want to add.
Hence, ensure to modify the username with the user of
your choice.
Command: adduser username
c. Password is the required command to create a password for
this new user.
Command: passwd username
Important: At the prompt, please create and reconfirm the
password for the new user. A strong and complex alphanumeric
password is recommended to secure the user’s account.
Also Read: How To upload website Files and Database
Using cPanel
Create a Group in CentOS:
Creating a group in CentOS is a straightforward process. You
must use the Groupadd command followed by the New Group’s
Name.
Please check the following.
Command: groupadd THE-NEW-GROUP-NAME

3. For sudo enable-user, use the following:
Command: sudo groupadd THE-NEW-GROUP-NAME
Also Read: Reduce CSF load with CWP
Add User to the Group in CentOS:
Before understanding how to add a user to the group, it is
substantial to know what is a “Wheel Group” or a “Wheel User
Group?”
Wheel Group is a special group in a Linux distro whose
members/users have root (administrative) privileges to perform
tasks similar to root admins.
Wheel Group:
To add a username to the Wheel Group, you must type in the
following command.
Command: usermod -a -G wheel username
Multiple Groups:
If you wish to add a username to multiple groups, the following
command is for you.
Command: usermod -a -G group1,group2,group3 username
Caution: Ensure to replace the word username with the actual
user’s name.

4. Also Read: What is FTP & How to Create an FTP Account In
cPanel?
Testing sudo access on a newly
created user account in CentOS:
Before achieving this task, you must first switch to the newly
created user account. Use the following command.
Command: su - username
Now that you have switched to the newly created user account,
verifying whether sudo works with this user is mandatory. Decide
upon a command that you wish to execute with superuser
privileges. Simply write “sudo” at the beginning of that command
to see if it performs as expected.
Only the root user has access to the content list of the /root
directory. You can run the following command from this newly
created user.
Command: sudo ls -la /root
Caution: If you are using sudo for the 1st time (in this session),
the system will prompt you to enter the correct password for this
new user. Please type in the correct password to proceed with
the task.
Source
https://www.hostitsmart.com/manage/knowledgebase/236/Your-
Practical-Guide-to-Creating--Users-and-Groups-in-CentOS7.html