Create a Shared Group

Several school assistants need access to the same report folder. Instead of treating each person as the owner of every file, you can define a group that represents the shared role. A Linux group has a name and a numeric group ID, and accounts can have group memberships.

Let's create the school-reports group. This prepares a useful identity for later access rules, but it does not enroll anyone or change a file automatically. We will keep those later steps explicit so shared access is understandable.

Prepare the example

Use the disposable VM with administrative authorization. Check whether school-reports already exists before running groupadd. The chosen name represents a role, not a directory that this command will create.

Bash · Linux terminal

sudo groupadd school-reports
getent group school-reports

Expected behavior; machine-dependent details

A group record; assigned GID varies.

sudo groupadd school-reports creates the group record according to local defaults. getent group school-reports then displays its lookup result, including the numeric group ID. The exact number is chosen or configured on that system; it is not a fixed value to memorize.

At this point, do not assume assistants have gained access to a report. Enroll an account using the appropriate membership operation, assign the intended file or directory group, and choose permission bits that grant the group's required access. A group name is an ingredient in that policy, not a complete access policy by itself.

Groups let several Linux users share access rules without giving identical permissions to everyone on the system. A group has its own name and numeric group ID.

Understand what a Linux user group is

In Linux, a group is a collection of users. Groups help system administrators manage permissions efficiently. For example, instead of setting permissions for each user, you can assign permissions to a group and add users to that group.

Open a terminal before creating the group

Let’s begin by opening your terminal. You can do this with:

Ctrl + Alt + T

Step 2: Check Existing Groups (Optional)

If you want to see the current groups on your system:

cut -d: -f1 /etc/group

root
daemon
bin
sys
...

Step 3: Create a New Group

We’ll use the groupadd command to create a new group. For example, to create a group named devteam:

sudo groupadd devteam

You’ll be prompted for your password if you’re not the root user.

Step 4: Verify the Group Was Created

Let’s check if the group was successfully created:

getent group devteam

devteam:x:1002:

This means the group exists and currently has no users.

Step 5: Add a User to the Group

To add an existing user (like john) to the new group:

sudo usermod -aG devteam john

The -aG flag appends the user to the group without removing them from others.

Step 6: Apply Group Changes

To make group changes take effect, either log the user out and back in, or use:

newgrp devteam

Step 7: Confirm User's Groups

You can confirm the user's group membership with:

groups john

john : john devteam

Create and verify Linux groups

You’ve successfully created a new user group and added a user to it. Group management is key to secure and scalable Linux system administration.

Your task: Does groupadd automatically move every report into that group?

Use the disposable VM with administrative authorization. Check whether school-reports already exists before running groupadd. The chosen name represents a role, not a directory that this command will create.

Bash · complete example for this question

sudo groupadd school-reports
getent group school-reports

Expected behavior; machine-dependent details

A group record; assigned GID varies.

Worked answer

No; file group ownership must be set separately.

Creating the group does not move reports or alter their ownership. A file group is separate metadata changed by an ownership operation. Group membership is separate again. Check each part instead of expecting a group name that resembles a folder to connect them automatically.

Use groups to represent shared roles, then make membership and file-access choices deliberately. Verify the created record before using its name in another command. The useful question is which people need which operations on which files, not simply whether a group exists.