Administration of Red Hat Enterprise Linux (2025)

Navigate the Linux file system using absolute and relative paths, the current directory, and identify regular, directory, executable, symbolic link, and device files with file and ls -la.

Create files with touch and text with cat or vi, create directories with mkdir and -p, and list or view contents using ls, ll, more, less, head, and tail.

Learn how to copy, move, rename, and remove files and directories with cp, mv, and rm, using -i prompts and -r for recursive directory operations.

Clarify how ext file system attributes govern delete, modify, rename, and compress operations on files and directories using lsattr and chattr, including append, immutable, and synchronous.

Master the find command to locate files and apply actions with dash exact, changing permissions from 777 to 644, deleting files, and filtering by type, name, owner, and emptiness.

Learn to find files larger than 100 megabytes and produce a long listing saved to /tmp/big_files using the find command with size and exec options, plus megabyte size notation.

Learn to view and interpret file permissions with ls -l and ls -lg, distinguish user, group, and others, and use chmod to set read, write, and execute rights.

Discover how to manage Linux file and directory permissions by creating items, applying chmod settings (0700, 0711, 0777, 0000, 644), and using recursive, umask, and ownership commands to control access.

Master group management in Red Hat Enterprise Linux by creating groups with groupadd, assigning users with usermod, and applying setgid on the opt-myproject directory to streamline project file collaboration.

Learn Vim basics by switching between insert and normal modes, navigating with h j k l and word commands, using search, percent, and visual mode for editing.

Practice creating and editing a new file in vim by opening text1.txt, entering insert mode, typing text, and saving your changes with wq.

Navigate vim with h j k l and zero or dollar for line edges. Edit with i, a, c, d; cc, dd, and yy, and tilt case.

Master Vim navigation by scrolling with ctrl f/b/d/u, moving by line and screen, using z commands to keep the cursor, and searching with / and n for multiple results.

Open vim to a specific line or pattern, or in read-only mode, and recover edits after a crash; save and exit with :w, :q, :wq, or :x.

Install vim on Linux, macOS, and Windows, then practice navigation (h, j, k, l, 10J, 20K, W, B, $, 0), enter insert mode with I, and exit with :q.

Learn essential Vim editing and navigation commands, including moving to screen and document positions, text insertion, copying, deletion, and undo/redo, for efficient Linux editing.

Practice vim navigation with hands-on exercises: jump between paragraphs with curly braces, and move with h, m, l and 0, $, gg, G.

Master Vim fundamentals through modal navigation, including normal and insert modes, efficient movement, searching, editing, yanking, and search-and-replace, with tips for macros and multiple-file work.

Explore Vim from basic file creation to advanced text manipulation, with navigation, deletion, and yanking, and efficient editing. Use visual mode, substitutions, and window and buffer management.

Practice text editing in Vim by creating a file, entering insert mode, and performing edits such as replacing words, deleting content, undoing changes, and using motion and command sequences.

Practice advanced Vim editing in exercises, reorder sections, cut and paste blocks, and annotate scripting languages for web development and system administration.

Master advanced vim techniques for editing, navigation, and multi-window workflows, including opening at specific lines, read-only mode, dot command, substitutions, and saving copies across files.

Navigate and edit multiple files in Vim by opening several buffers, switching between files with next and previous, using horizontal and vertical splits, editing new files, and saving with wqa.

Discover how to search words in files with grep and count results using -n, -c, and -v, then count words and lines with wc for quick document insight.

Learn to use pipes to streamline tasks by connecting who to sort and wc -l, producing a sorted user list and a login count without temporary files.

Learn how process niceness sets priority across 40 values from minus 20 to plus 19, with default zero, viewable via ps or top, and adjustable with nice and renice.

Learn how to control Linux processes with signals, using kill and pkill to send signals like SIGHUP, SIGINT, SIGTERM, and SIGKILL for graceful or forced termination and configuration reload.

Master changing passwords with passwd, including entering the old and new password, then grasp shell and environment variables, assign and access them, and understand how path directs command lookup.

Learn chaining operators in Linux commands, including ampersand for background jobs, semicolon for sequential execution, and end operator, or operator, and not operator to control flow by success or failure.

Perform exit, reboot, power off, and shutdown on Red Hat Linux, using options like -h, -p, -r, and timed schedules, while understanding root privileges and authentication requirements.

Learn how bash history works, including startup and initialization files, history loading from ~/.bash-history, and controlling history with HISTSIZE and HISTFILESIZE, plus commands to view, edit, and search history.

Learn to view, create, and manage shell aliases using the alias and unalias commands, make per-session or permanent aliases via .bashrc, and switch users to see alias behavior.

Learn to monitor a command's changing output with watch, adjust refresh with -n, highlight differences with -d, and watch file growth and log updates.

Learn how to gain administrative privileges on red hat linux using sudo and su, configure sudoers with visudo, and review sudo activity in /var/log/auth.log.

Master scheduling one-time and recurring tasks with atd and cron-d, including job submission, time formats, and access control via allow and deny files.

Master rpm package management using key query options (-q, -qa, -qc, -qd) and install options (-F, -I, -U, -H, -V) to manage packages and dependencies.

Manage Linux packages with yum, the rpm front-end, configuring repositories, caching, and logging via /etc/yum.conf and yum-config-manager to ensure secure, consistent Red Hat updates.

Manage hostnames in Red Hat Enterprise Linux. Learn what a hostname is, where it’s stored, how to view it, and set it permanently with hostnamectl, /etc/hostname, and update /etc/hosts.

Use the ip command to inspect interfaces with ip link show, view addresses with ip address show, and add addresses with ip addr add on Red Hat Enterprise Linux.

Configure networking with the Network Manager command line interface nmcli, and manage devices and connections, including DHCP and static configurations, using nmcli-con-show, nmcli-dev-status, and nmcli-con-add.

Register Red Hat Enterprise Linux 9 from the command line to access updates, support, and repositories, then attach, verify, and manage subscriptions with subscription-manager commands.

Gain superuser access in Red Hat Enterprise Linux with su and sudo, switch to root or other users, and understand dash versus non-dash shells and wheel group privileges.

Demonstrate gaining superuser access with sudo and su, compare non-login and login shells, and practice managing home and path variables while running commands as root and a normal user.

Create, modify, and delete Linux user accounts using useradd, usermod, and userdel, set passwords with passwd, switch to root with sudo su -, and verify entries in /etc/passwd.

Create, modify, and delete groups with groupadd, groupmod, and groupdel; use -g or -r to assign system gids, and use usermod to set primary or supplementary groups.

Create operator and admin supplementary groups, add users to these groups, verify memberships with id and /etc/group, and grant sudo privileges via /etc/sudoers.d/admin.

Learn how Red Hat Enterprise Linux manages user passwords with etc.shadow, includes password aging and expiration, and uses account controls like locking and no-login shells.

Practice managing user passwords by forcing first-login changes, setting 90-day password aging, and expiring accounts after 180 days, using sudo, ch, date, and vim.

Practice managing local users and groups in red hat enterprise linux. Create a consultants group with gid 40000, add consultants, and configure sudo and account expiration and 15-day password policies.

Lock the root account using sudo passwd -l root and verify it is locked. Use sudo for privilege escalation and harden ssh by disabling root login.

Create a restricted service account and a sudoers.d profile granting specific commands without a password on all servers, then test systemctl and journalctl access.

Build a role-based access control system using groups, create web, db, and backup admin groups, provision users, and configure group-based sudoers rules for service management.

Examine environment security and sudoers to prevent privilege escalation by enforcing a secure path, environment reset, and removal of dangerous variables like ldpreload.

Explore pseudo session management for security in shared environments and configure timeouts with a sudoers.d file. Define default timeouts for quick, long, and secure sessions and test with password prompts.

Analyze effective sudo policies using sudo -l to view user rights, defaults, and group-based rules. Debug command execution with -u and -L, and interpret policy messages.

Remove test users and groups, including service admin and web, db, backup, secure, and EMV users. Archive sudoers files under etc/sudoers.d/archive and verify the sudoers integrity.

Learn sudoers best practices and how to set up a configuration repository with service, web admin, and environment security role files to enforce least privilege.