Managing Users and Groups in Linux: Step-by-Step Admin Guide

Managing users and groups is one of the most common—and most security-sensitive—tasks in Linux administration. Every SSH login, service account, cron job, file permission, and production deployment ultimately depends on correct identity and authorization decisions. When these decisions are made ad hoc (hand-created users, inconsistent group naming, “temporary” sudo rules that never get removed), you end up with fragile operations and persistent privilege risk.

This guide walks through managing users and groups in Linux as an end-to-end practice. You’ll start with how Linux represents identities (UIDs, GIDs, and the account databases), then move into safe account creation, lifecycle management, password and lock policies, group design, and privilege delegation with sudo. Along the way, you’ll see realistic scenarios that mirror what admins deal with: onboarding engineers to a production fleet, granting a vendor limited access, and standardizing service accounts for applications.

Although Linux distributions vary, the core concepts and files are shared across most modern systems (Debian/Ubuntu, RHEL/CentOS/Rocky/Alma, SUSE). Where behavior differs, the guide calls it out explicitly.

How Linux represents users and groups

Before running commands like useradd or usermod, it helps to understand what Linux is actually changing. Linux identifies a user primarily by a numeric UID (user ID). The username you type at a prompt is a label mapped to that UID. Similarly, groups are mapped to numeric GIDs (group IDs). File ownership and many permission checks are based on these numbers, not the textual names.

This matters operationally because when you move files between systems, restore from backups, or mount shared storage, the UID/GID consistency becomes critical. If two servers assign different UIDs to the same username, files can appear “owned by the wrong person,” and access decisions can surprise you.

Most local identity information is stored in a few canonical files:

/etc/passwd contains the user database (name → UID/GID mapping, home directory, login shell). Despite the name, it does not store password hashes on modern systems.
/etc/shadow stores password hashes and aging/expiry metadata. It is readable only by privileged processes.
/etc/group contains groups and their member lists.
/etc/gshadow stores group passwords (rarely used) and administrative group membership metadata on many distributions.

In enterprise environments, these files may be supplemented—or replaced for interactive logins—by directory services such as LDAP, Active Directory (via SSSD/Winbind), or cloud identity providers. Even then, local users and groups remain relevant for break-glass access, service accounts, and early-boot processes.

Reading `/etc/passwd`, `/etc/shadow`, and `/etc/group`

You don’t need to memorize the file formats, but understanding them makes it easier to audit and to recover from mistakes.

A typical /etc/passwd line looks like this:

getent passwd root

Output commonly resembles:

root:x:0:0:root:/root:/bin/bash

Fields (colon-separated) are:

Username
Password placeholder (x indicates the real hash is in /etc/shadow)
UID
Primary GID
GECOS/comment field (often full name)
Home directory
Login shell

To view shadow information safely, use getent (which respects NSS—Name Service Switch—and can return LDAP/SSSD users too):

bash
sudo getent shadow someuser

For groups:

bash
getent group
getent group sudo

This is a practical habit: use getent for queries because it shows the system’s effective view (local files plus any remote identity providers), rather than only /etc/*.

UID and GID ranges (system vs human accounts)

Most distributions reserve low UIDs/GIDs for system accounts used by daemons and packages. Human user accounts typically start at 1000 on Debian/Ubuntu and often 1000 or 5000+ depending on RHEL family configuration. The exact defaults are controlled by /etc/login.defs and sometimes distribution tooling.

You’ll see terms like system account (non-interactive account for a service) and login account (interactive user). A system account often has:

No password set
A shell like /usr/sbin/nologin or /bin/false
A home directory that may not exist or is set to a service-specific path

Keeping these categories distinct reduces confusion and limits lateral movement opportunities when a service is compromised.

Planning a user and group strategy (before touching commands)

User/group management becomes messy when you treat it as a series of one-off tickets. A small amount of upfront design prevents long-term drift.

Start by deciding what groups represent in your environment. In many fleets, groups map to one of these models:

Functional access groups: app-deploy, db-readonly, log-readers
Team groups: platform, sre, data-eng
Resource groups aligned to Unix permissions: docker, www-data, postgres

Functional groups tend to scale better across many systems because they describe what a user can do, not where they sit organizationally. Team groups can still be useful, but they often need translation into concrete access.

Also decide how you’ll handle privilege escalation. In Linux, a common practice is to grant minimal privileges via sudo to a group (for example, sudo on Ubuntu or wheel on RHEL). You can also create custom sudoers groups for specific administrative capabilities.

Finally, consider UID/GID consistency across systems. If you rely on local users (not centralized identity), you should define a mapping convention—for example, allocate a range for service accounts (200–999) and another for humans (10000+), and reserve blocks per team. In centralized environments (LDAP/AD), this is usually handled centrally.

This planning becomes immediately relevant in the first real-world scenario.

Real-world scenario 1: onboarding engineers to production

Imagine you run a small production fleet with a mix of Ubuntu and Rocky Linux servers. Engineers need SSH access and the ability to restart services, inspect logs, and deploy code. If you simply add each engineer to sudo (or wheel) everywhere, you’ve granted broad administrative rights with no segmentation.

A more durable plan is to:

Create a prod-ssh group that grants SSH login via sshd_config or PAM access controls (where used).
Create a svc-restart group with sudo rules limited to systemctl restart for a specific set of services.
Create a log-readers group with read access to log directories (or use ACLs).

With that model in mind, the remainder of this guide shows how to implement it consistently.

Creating users safely: `useradd`, `adduser`, and defaults

Linux provides multiple user creation tools. On Debian/Ubuntu, adduser is a higher-level, interactive wrapper around useradd that tends to pick sensible defaults. On RHEL-family systems, useradd is commonly used directly. Both approaches are valid; the key is to be explicit about security-relevant fields.

Inspecting and setting defaults

Defaults for useradd are stored in /etc/default/useradd and related configuration files. You can view them with:

bash
useradd -D

This prints defaults like the base home directory, default shell, and whether a mail spool is created. Password aging defaults come from /etc/login.defs.

For consistent behavior across servers, you can template these files through configuration management (Ansible, Puppet, Chef) rather than relying on distribution defaults.

Creating a standard interactive user

To create a user with a home directory and a specific shell:

bash
sudo useradd -m -s /bin/bash -c "Jane Doe" jdoe
sudo passwd jdoe

The -m flag creates the home directory (for example /home/jdoe) and populates it with skeleton files from /etc/skel. The comment field (-c) is optional but helps later audits.

On Debian/Ubuntu, many admins prefer:

bash
sudo adduser jdoe

adduser will prompt for a password and user details, then create the home directory and default groups. If you use it, be aware that automation is easier with useradd because it is non-interactive.

Creating a system account for a service

For a non-interactive service account, use a system UID range and disable login:

bash
sudo useradd --system --home /var/lib/myapp --shell /usr/sbin/nologin myapp

Whether --system chooses the UID range you expect depends on distribution settings. Verify with:

bash
id myapp
getent passwd myapp

If the service needs ownership of directories, create those directories and set ownership explicitly rather than relying on implicit defaults.

Avoiding common creation pitfalls

A frequent mistake is creating a user without -m, then later adding a home directory manually. This can lead to incorrect ownership or missing default files. Another is leaving the default shell for service accounts as /bin/bash, which can enable interactive logins if SSH keys are later added.

A third issue is inconsistency across servers: one engineer gets UID 1001 on one host and UID 1005 on another. If you use NFS shares, rsync backups, or container bind mounts across hosts, those mismatches become operational problems. If you cannot centralize identities, at least document and enforce UID assignment ranges.

Managing passwords, locks, and account aging

Identity management is not only about creating accounts; it’s about controlling when they can authenticate and under what conditions. Linux tracks password and expiry metadata per user, primarily in /etc/shadow.

Setting and changing passwords

Interactive password changes are done with passwd:

bash
sudo passwd jdoe

Users can change their own password with passwd as well, subject to PAM policy (for example, minimum length or complexity enforced via pam_pwquality).

To set a password non-interactively in automation, you can use chpasswd:

bash
echo 'jdoe:Str0ngTempPass!' | sudo chpasswd

Be careful with this pattern: it can leak secrets into shell history or logs. Prefer setting an expired temporary password and forcing change on first login, or use SSH keys and avoid passwords entirely for admin access.

Locking and unlocking accounts

To temporarily prevent a user from authenticating with a password, lock the account:

bash
sudo passwd -l jdoe

To unlock:

bash
sudo passwd -u jdoe

Locking typically prepends an invalid character to the password hash in /etc/shadow, making it unusable. This does not necessarily disable SSH key authentication if keys remain present and SSH is configured to allow them. If you need to fully disable access, also consider:

Removing or restricting ~/.ssh/authorized_keys
Setting the shell to /usr/sbin/nologin
Using SSHD AllowUsers/AllowGroups or PAM access controls, depending on your environment

A common lifecycle approach is: lock first (immediate access removal), then later delete after a retention period.

Expiring accounts and forcing password change

Account expiration controls the date after which a login is blocked. Password expiration controls whether the password must be changed.

Use chage to inspect and set these values:

bash
sudo chage -l jdoe

To force a password change on next login:

bash
sudo chage -d 0 jdoe

To set an account expiration date:

bash
sudo chage -E 2026-03-31 contractor1

These controls are particularly useful for contractors and vendors, which leads into a scenario you can model.

Real-world scenario 2: time-bound vendor access

Suppose you’re engaging a storage vendor to troubleshoot a SAN integration. They need SSH access to two hosts and the ability to run a specific diagnostic tool requiring elevated privileges.

A safe pattern is:

Create a dedicated account like vendor_san with a clear comment field.
Set an account expiry date aligned with the contract.
Grant sudo privileges only for the required commands, preferably with no shell access beyond that scope.

This makes offboarding deterministic: even if someone forgets to remove the account, it will expire. Later in the guide, you’ll implement the least-privilege sudo rule safely using visudo.

Modifying users: `usermod` and careful changes

Once users exist, you will frequently need to adjust attributes: groups, home directories, shells, and account metadata. The usermod command is the primary tool.

Changing a user’s shell

To change an interactive user’s shell:

bash
sudo usermod -s /bin/zsh jdoe

To disable interactive login by setting a non-login shell:

bash
sudo usermod -s /usr/sbin/nologin vendor_san

Use getent passwd vendor_san to confirm changes.

Changing the home directory (and moving content)

Changing a home directory path is more sensitive than it looks because many applications store absolute paths in configuration.

To change and move the existing directory:

bash
sudo usermod -d /home/jane.doe -m jdoe

The -m flag moves the content to the new location. Without -m, you’ll update /etc/passwd but leave files behind.

Renaming a user

Renaming changes the username label but not the UID. This can be useful when someone changes their name or when you want to standardize naming.

bash
sudo usermod -l jane.doe jdoe
sudo usermod -d /home/jane.doe -m jane.doe

After renaming, validate SSH keys paths, cron jobs (crontab -l -u oldname), and any service references. If scripts or sudo rules referenced the old username explicitly, update them.

Changing UID/GID (be cautious)

Changing a UID affects file ownership everywhere. This is disruptive on a running system and should be done only with a plan.

To change a UID:

bash
sudo usermod -u 10500 jdoe

Then you must fix ownership across the filesystem. A common approach is to find files owned by the old UID and chown them:

bash
OLD_UID=1001
NEW_USER=jdoe
sudo find / -xdev -uid "$OLD_UID" -exec chown -h "$NEW_USER" {} +

This is intentionally constrained with -xdev to avoid crossing filesystems unexpectedly. Even with care, this can be expensive on large disks and can miss files on other mounts.

In practice, if you need consistent UIDs across many systems, centralize identity (LDAP/AD) or provision local accounts with explicitly assigned UIDs from a documented scheme.

Removing users: `userdel`, data retention, and risk management

User removal is where operational needs and security needs often conflict. Security wants immediate removal; operations may need to retain home directories, logs, and ownership for forensics or compliance.

Lock vs delete

A common approach is:

Immediately lock the account and remove SSH keys (fast access removal).
After a defined retention period, delete the account.

Locking is reversible; deletion is not.

Deleting a user

To remove a user but keep their home directory:

bash
sudo userdel jdoe

To remove the user and their home directory/mail spool:

bash
sudo userdel -r jdoe

Be careful with -r on systems where home directories might contain application data or shared files. Deleting the account does not automatically reassign ownership of files elsewhere on the filesystem; those files will remain owned by the numeric UID, which may later map to a different user if UIDs are reused.

To reduce that risk, avoid UID reuse policies, or explicitly archive and reassign ownership of important paths before deletion.

Groups in depth: primary vs supplementary groups

Groups are how you scale permissions. Each user has one primary group (the GID field in /etc/passwd) and can have many supplementary groups (listed in /etc/group or returned via NSS).

The primary group is used when the user creates files (unless overridden by directory permissions like the setgid bit). Supplementary groups extend access checks.

Creating and managing groups

To create a group:

bash
sudo groupadd app-deploy

To modify a group name:

bash
sudo groupmod -n app-release app-deploy

To delete a group:

bash
sudo groupdel app-release

Deleting a group does not change files owned by that GID; they will remain owned by the numeric ID. As with UIDs, reusing GIDs can cause ownership confusion.

Adding users to groups

To add a user to supplementary groups:

bash
sudo usermod -aG app-deploy,log-readers jdoe

The -a (append) flag is crucial. Without it, -G replaces the user’s supplementary groups, which can accidentally remove needed access (for example, docker group membership).

To verify group membership:

bash
id jdoe
groups jdoe

Changes may require the user to log out and back in to refresh group membership in their session.

Primary group patterns: user private groups vs shared primary groups

Many distributions use “user private groups” (UPG): when you create jdoe, it also creates a group jdoe and sets it as the primary group. This reduces accidental cross-user file access because default umask settings tend to make files group-readable.

In some environments, you may prefer setting a shared primary group for a team directory workflow. If you do this, you must combine it with directory permission controls (like setgid on directories) to ensure files stay group-owned correctly.

File permissions, shared directories, and the role of groups

Users and groups become practical when applied to filesystem permissions. Standard Unix permissions are the familiar rwx bits for user/group/other. For shared administration workflows—deploy directories, shared logs, data drops—groups are usually the simplest control plane.

Building a shared directory with setgid

Suppose you want a shared directory /srv/app/releases where members of app-deploy can write, and you want all new files to inherit the app-deploy group automatically.

You can do this by setting group ownership and the setgid bit on the directory:

bash
sudo mkdir -p /srv/app/releases
sudo chgrp app-deploy /srv/app/releases
sudo chmod 2775 /srv/app/releases

The leading 2 sets the setgid bit on the directory. With this, files created inside inherit the directory’s group, which avoids the “some files are owned by jdoe:jdoe and others by alice:alice” problem.

This is where group design pays off: a stable functional group (app-deploy) gives a clean mapping to a real permission boundary.

When you need ACLs

Traditional permissions can be too coarse when multiple groups need different access. POSIX ACLs (Access Control Lists) allow per-user or per-group permissions beyond the single group owner.

While ACLs are powerful, they are also easier to forget and harder to audit than simple group ownership. Use them when you genuinely need exceptions, and document them.

To grant log-readers read access to /var/log/myapp without changing the owning group:

bash
sudo setfacl -R -m g:log-readers:rx /var/log/myapp
sudo setfacl -R -d -m g:log-readers:rx /var/log/myapp

The -d sets default ACLs so new files inherit permissions.

To view ACLs:

bash
getfacl /var/log/myapp

ACL usage is a good example of why you should keep groups meaningful and limited. If every access request turns into a one-off ACL, your permission model becomes opaque.

Privilege management with sudo: principle of least privilege

On modern Linux systems, sudo is the standard tool for controlled privilege escalation. It allows a permitted user to run specific commands as root (or another user) based on policy.

The core configuration file is /etc/sudoers, but you should not edit it directly with a regular editor because syntax errors can lock you out of administrative access. Use visudo, which validates syntax and handles safe editing.

Understanding how sudo rules are evaluated

Sudo rules can be based on:

Usernames
Groups (prefixed with %)
Hostnames (in more complex sudoers setups)
Run-as targets (root or other users)
Command whitelists

The safest pattern is group-based access with command restrictions, because it scales better than per-user rules and supports easy onboarding/offboarding by adjusting group membership.

Creating a minimal sudo rule for a group

Continuing the earlier onboarding scenario, suppose members of svc-restart should be able to restart two services only: nginx and myapp.

Create a drop-in file under /etc/sudoers.d/:

bash
sudo visudo -f /etc/sudoers.d/svc-restart

Add:

sudoers
%svc-restart ALL=(root) NOPASSWD: /bin/systemctl restart nginx, /bin/systemctl restart myapp
%svc-restart ALL=(root) NOPASSWD: /bin/systemctl status nginx, /bin/systemctl status myapp

A few details matter here:

Use absolute paths to commands (/bin/systemctl). Run command -v systemctl to confirm on your distro (often /bin/systemctl or /usr/bin/systemctl).
Keep the command list as narrow as practical. Allowing systemctl without arguments is effectively broad root.
Use a dedicated file in /etc/sudoers.d/ with a descriptive name; this is easier to manage and audit.

Whether to use NOPASSWD is a policy decision. In many production environments, admins require password entry for interactive sudo, but allow NOPASSWD for narrow, operationally necessary commands. If you require passwords, remove NOPASSWD:.

Testing sudo access safely

From the user account, list allowed sudo commands:

bash
sudo -l

Then attempt the permitted command:

bash
sudo systemctl status myapp

This test-driven approach helps ensure your rule is as intended before rolling it out broadly.

Real-world scenario 3: delegating safe production operations

Consider a platform team that wants to let on-call engineers mitigate incidents without granting full root. They need to restart services, tail logs, and view system status, but not install packages or change firewall rules.

A practical implementation combines multiple controls:

Group-based filesystem access (log-readers group on application logs, possibly via ACLs).
Narrow sudo rules (svc-restart can restart only named units; a separate svc-status group can run read-only commands).
No direct root SSH logins (common hardening practice), so every privileged action is attributable to a user.

This setup reduces blast radius while still enabling incident response. It also makes audits more meaningful: sudo logs show exactly which command ran and by whom.

User and group management interacts heavily with SSH. Even if you don’t manage SSH here, you should connect identity decisions to remote access policy.

Restricting SSH logins with AllowGroups

If you want only members of a specific group (for example prod-ssh) to be able to log in via SSH, you can configure sshd accordingly. The exact configuration depends on your existing policies, but the approach is consistent.

In /etc/ssh/sshd_config:

text
AllowGroups prod-ssh

Then reload SSHD (command varies slightly by distro, but commonly):

bash
sudo systemctl reload sshd

Be cautious when changing SSH access rules on remote systems. Always keep an existing session open while validating new settings, and ensure at least one break-glass path exists.

The point is not that AllowGroups is always the right tool, but that group membership can become a clean operational lever: add a user to prod-ssh to grant access; remove them to revoke access.

Managing SSH keys as part of account lifecycle

If you use SSH keys, user offboarding must include removing or disabling authorized keys. Locking the password does not block key-based authentication unless additional controls are in place.

Operationally, this is another reason to avoid local snowflake management: if you manage authorized_keys manually across many hosts, offboarding is error-prone. Centralized identity, configuration management, or a trusted access proxy can help, but even without those, having a documented lifecycle checklist for local accounts is necessary.

Auditing users and groups on a system

Regular audits catch drift: old accounts, unexpected sudo privileges, and unused groups. Auditing also helps during incident response when you need to answer “who could have accessed this system?”

Listing local users and identifying interactive accounts

To list accounts, you can parse /etc/passwd, but getent passwd is generally better because it includes remote users if configured.

A quick view of “likely interactive” accounts is to filter by shell:

bash
getent passwd | awk -F: '$7 !~ /(nologin|false)$/ {print $1 "\t" $3 "\t" $7}'

This is not perfect—some service accounts may have real shells, and some interactive accounts may use unusual shells—but it’s a useful starting point.

Checking group membership and privileged groups

List members of a group:

bash
getent group sudo
getent group wheel
getent group svc-restart

Then validate sudo permissions directly:

bash
sudo -l -U jdoe

This prints effective sudo privileges for a user (including group-based rules), which is much more reliable than eyeballing sudoers files.

Reviewing password and account expiry status

To identify accounts with expired passwords or accounts near expiry, use chage:

bash
sudo chage -l jdoe

On fleets, you typically want automation that collects these signals, but even on a single host, it’s valuable to check contractor accounts periodically.

Finding orphaned files (no longer mapped to a user/group)

If you delete users or groups, files may remain owned by numeric IDs with no corresponding name. This isn’t inherently wrong, but it’s often a sign of incomplete lifecycle management.

To find files with no known owner (within a filesystem):

bash
sudo find /var -xdev -nouser -o -nogroup

Investigate before changing ownership; orphaned ownership can be evidence you need to retain.

Standardizing workflows across multiple servers

If you manage more than a handful of systems, consistency becomes the primary challenge. Even if you don’t have full configuration management, you can still apply disciplined practices: predictable naming, dedicated sudoers drop-ins, and scripts that are idempotent (safe to run repeatedly).

Using scripts carefully for repeatable identity changes

For small environments, a simple shell script can prevent operator error. The goal is not to replace proper tooling, but to ensure the same steps happen every time.

Example: create an interactive user with standard groups and force password change on first login:

bash
#!/usr/bin/env bash
set -euo pipefail

USER="$1"
COMMENT="${2:-}"

# Create user if missing

if ! id "$USER" >/dev/null 2>&1; then
  sudo useradd -m -s /bin/bash -c "$COMMENT" "$USER"
fi

# Ensure baseline groups

sudo usermod -aG prod-ssh,log-readers "$USER"

# Set a temporary password (provide securely) and force change

# echo "$USER:TempPassHere" | sudo chpasswd

sudo chage -d 0 "$USER"

echo "Provisioned $USER"

In practice, you would avoid embedding passwords and instead enroll SSH keys, but the structure shows the idempotent checks (id user), explicit group membership, and explicit policy (chage -d 0).

When to prefer centralized identity

Local account management scales poorly when:

You have frequent onboarding/offboarding.
You need consistent UID/GID mapping across many hosts.
You need strong auditability and rapid revocation.

Centralized identity (LDAP/AD with SSSD) solves many of these problems, but it introduces its own operational considerations (availability, caching, bootstrap access). Even in centralized setups, keep at least one local break-glass account with tightly controlled credentials and logging.

Service accounts and application-oriented group design

Applications often need a dedicated identity to own files, bind to sockets, or run processes under a non-root user. Treat these as first-class design elements rather than incidental artifacts.

Creating a service account and group for an application

Suppose you’re deploying an in-house service myapp that writes to /var/lib/myapp and /var/log/myapp.

A typical approach is:

Create a system user and group.
Create directories and assign ownership.
Ensure the service runs under that account (via systemd unit configuration, not covered here in detail).

Commands:

bash
sudo groupadd --system myapp
sudo useradd --system --gid myapp --home /var/lib/myapp --shell /usr/sbin/nologin myapp

sudo mkdir -p /var/lib/myapp /var/log/myapp
sudo chown -R myapp:myapp /var/lib/myapp /var/log/myapp
sudo chmod 0750 /var/lib/myapp /var/log/myapp

This pattern reduces the blast radius of a compromise: the service has only the permissions it needs, and it cannot log in interactively.

Coordinating admin access to service-owned data

Your admins may need to read logs or inspect state directories without becoming root. You can support this by creating a separate functional group and granting read-only access.

For example:

bash
sudo groupadd log-readers
sudo setfacl -R -m g:log-readers:rx /var/log/myapp
sudo setfacl -R -d -m g:log-readers:rx /var/log/myapp

This complements your sudo design: you don’t want to grant sudo cat /var/log/myapp/* if you can grant safe read access via the filesystem.

Special considerations: `root`, `su`, and administrative hygiene

The root account (UID 0) bypasses discretionary access controls. Your goal is not to avoid root entirely, but to make root use intentional, attributable, and limited.

Prefer sudo over shared root access

Using sudo means actions are logged with the initiating username. Shared root passwords or routine su - usage can make accountability harder unless you have strong session logging.

If you do use su, understand that it typically requires the target user’s password (root’s password) and may bypass some sudo logging semantics. Many environments disable root SSH login and rely on sudo from named accounts.

Secure editing of privilege files

Always use visudo for:

/etc/sudoers
any file under /etc/sudoers.d/

This is not mere tradition; a syntax error can prevent all sudo operations, potentially locking you out of administrative recovery paths.

Operational hygiene: documentation, naming, and lifecycle consistency

At this point, you’ve seen the mechanics of managing users, groups, passwords, sudo privileges, and shared access. The remaining work is to keep the system clean over time.

A few practices that tend to pay off:

Use descriptive group names tied to capabilities (svc-restart, log-readers) rather than ad hoc names.
Keep sudo rules in dedicated /etc/sudoers.d/ files with a clear purpose, and keep command lists narrow.
Treat user creation and removal as lifecycle events with defined steps: create → grant access → review → revoke → lock → delete.
Regularly review privileged group membership (sudo, wheel, and any custom sudoers groups).

When you apply these practices consistently, “managing users and groups in Linux” stops being a reactive chore and becomes a predictable, auditable process that supports both uptime and security.

Managing Users and Groups in Linux: Step-by-Step Guide for Administrators