Ubuntu Server Mastery: Real-World Linux Admin Skills Course

Lesson 1 • Linux Architecture and Core Concepts

Covers kernel, shell, and user-space relationships that underpin every admin task. Establishes vocabulary used throughout the course.

Lesson 2 • Getting Help and Documentation

Introduces man pages, info docs, and online resources for self-sufficient troubleshooting. Reduces dependency on external support during real-world tasks.

Lesson 3 • Navigating the Command Line

Teaches essential Bash commands for file system navigation and text manipulation. Forms the operational baseline for all subsequent chapters.

Lesson 1 • Group Management and Membership

Explains primary and supplementary groups and their effect on resource access. Enables role-based access patterns without complex ACLs.

Lesson 2 • Advanced Access Control Lists

Extends permissions beyond the three-entity model using POSIX ACLs. Solves real-world scenarios where standard bits are insufficient.

Lesson 3 • Sudo and Privilege Escalation

Configures sudo to grant controlled root-level access without sharing the root password. Enforces accountability through command logging.

Lesson 4 • User Account Management

Covers creating, modifying, and deleting user accounts with correct UID and home directory settings. Directly supports secure server onboarding workflows.

Lesson 1 • RAID Concepts and Software RAID

Implements redundancy with mdadm for RAID 0, 1, 5, and 10 arrays. Protects data against disk failure in cost-sensitive deployments.

Lesson 2 • Disk Partitioning and Formatting

Uses fdisk, gdisk, and parted to create MBR and GPT partition tables. Prepares physical storage for file system creation.

Lesson 3 • Mounting and the fstab File

Configures persistent and on-demand mounts using /etc/fstab and systemd mount units. Ensures storage is available after reboots.

Lesson 4 • Logical Volume Management

Builds flexible storage pools with LVM physical volumes, volume groups, and logical volumes. Enables online resizing without downtime.

Lesson 1 • Firewall Management with UFW and nftables

Implements host-based firewalls using UFW for simplicity and nftables for advanced rules. Restricts traffic to only required services.

Lesson 2 • DNS Resolution and /etc/hosts

Configures stub resolver, systemd-resolved, and /etc/hosts for name resolution. Ensures reliable hostname lookups in isolated and connected environments.

Lesson 3 • Network Interface Configuration

Applies IP addresses, gateways, and DNS settings via Netplan and the ip command. Covers both DHCP and static assignment for server roles.

Lesson 1 • Snap Package Management

Installs and manages confined Snap packages alongside APT packages. Addresses use cases where newer upstream versions are required.

Lesson 2 • Unattended Upgrades and Patching

Automates security patching with unattended-upgrades and schedules maintenance windows. Reduces exposure time for known vulnerabilities.

Lesson 3 • APT Package Management

Uses apt and dpkg to install, upgrade, and remove packages with dependency resolution. Covers the full software lifecycle from search to purge.

Lesson 1 • systemd Service Management

Controls services with systemctl and interprets unit file syntax for custom services. Covers enable, disable, start, stop, and status workflows.

Lesson 2 • Scheduling Tasks with cron and systemd Timers

Automates recurring tasks using crontab syntax and systemd timer units. Compares both approaches for reliability and logging.

Lesson 3 • Boot Process and systemd Targets

Traces the boot sequence from firmware to login prompt and maps systemd targets to runlevels. Enables boot-time troubleshooting and optimization.

Lesson 4 • Monitoring and Controlling Processes

Uses ps, top, htop, and kill to inspect and manage running processes. Enables rapid response to runaway or unresponsive processes.

Lesson 1 • SSH Hardening and Key-Based Authentication

Replaces password authentication with SSH key pairs and restricts daemon settings in sshd_config. Eliminates the most common remote access attack vectors.

Lesson 2 • AppArmor Mandatory Access Control

Confines applications with AppArmor profiles in enforce and complain modes. Limits damage from compromised processes without rewriting application code.

Lesson 3 • Security Scanning and Vulnerability Assessment

Uses Lynis, OpenVAS basics, and CVE databases to identify and prioritise vulnerabilities. Translates scan output into actionable remediation tasks.

Lesson 4 • System Audit Logging with auditd

Configures auditd rules to record file access, privilege use, and authentication events. Produces evidence trails required for compliance and incident response.

Lesson 1 • Log Analysis and Pattern Detection

Applies grep, awk, sed, and logwatch to extract meaningful signals from log files. Converts raw log data into actionable operational intelligence.

Lesson 2 • Performance Tuning Fundamentals

Identifies CPU, memory, I/O, and network bottlenecks and applies targeted tuning parameters. Improves throughput and latency for production workloads.

Lesson 3 • Alerting and Monitoring Integration

Configures threshold-based alerts using Prometheus node exporter and Grafana dashboards. Enables proactive incident detection before users are affected.

Lesson 4 • System Logging with journald and rsyslog

Queries the systemd journal and configures rsyslog for persistent, structured log forwarding. Provides the data foundation for all monitoring and alerting.