Linux System Engineering and Administration for Beginners

Explore how to ask your computer basic questions and identify issues by examining its three core parts: the cpu, ram, and disk, and learn to monitor them by querying them.

Explore how to monitor cpu usage with top and htop, identify active processes, understand core counts and load averages (one-minute, five-minute, fifteen-minute), and safely manage processes with kill.

Master linux memory management using top and htop, explore memory, cache, and swap, and see how memory behavior impacts performance with real demos on linux mint.

Learn to analyze Linux disk usage using commands like ls, df -h, and du -h, inspect block devices, and isolate top space users while redirecting errors for concise summaries.

Learn how to monitor system performance by checking cpu cores, averages, ram availability, and disk usage, using terminal tools like top to sort and parse files.

Install and configure an Apache server, troubleshoot virtualization issues, and explore how Apache works under the hood with basic files to monitor services.

Install and troubleshoot apache2 on your Linux system using apt. Identify the machine IP and test access via localhost or the network IP, and resolve VirtualBox networking issues if needed.

Learn the basics of apache configuration, edit the index under /var/www/html, reload apache, and manage sites with sites-available and sites-enabled through symbolic links to enable the default site.

Install Nagios on Debian or Arch, verify with systemctl status, enable Apache modules for auth digest, test configuration, and confirm the Nagios web interface is reachable.

Install and run Nagios on a Debian-based system using apt, start the service with systemctl, and monitor a host’s status, CPU load, and services through a browser.

Follow along to configure packages with the package manager, start the appropriate systemd unit, and run a graphical interface on a bridge or real computer, then inspect the system status.

Explore the basics of network mapping and the theory behind scanning tools, from mapping a name to an IP address to scanning your local network for useful information.

Explore the host file (/etc/hosts) to map ip addresses to names, and compare it with dns to see why dns simplifies accessing websites.

Explore how dynamic DNS resolves host names on a home network by using a local DNS server, querying upstream services like Quad9, and understanding IP-to-name mappings.

Ping demonstrates how to test connectivity and latency by pinging google.com and 1.1.1.1 to verify DNS resolution, and by checking the default gateway 192.168.1.1.

Explore basic port theory and how ports label information a computer exchanges, including ssh on port 22, http and https on ports 80 and 443, and email on port 25.

Explore the legal considerations of using network scanning tools like nmap, emphasizing consent when testing ports. Learn safe, compliant ways to assess your own networks.

learn to use nmap to scan your linux devices and local network, identify open ports, inspect services like ftp, ssh, telnet, and http, and explore using arp-scan with permission.

Set up pi-hole on Arch and Debian, test domain queries with dig, configure static IPs on the router, and ensure reliable DNS caching and uptime.

Learn how to install Pi-hole on Debian or Arch, turning your home network into a DNS-based blocker that filters ads and malicious domains for faster, safer internet.

Build basic Linux system administration skills by understanding host values, adding entries, testing network responsiveness with ping, and learning about ports and local port scanning while avoiding scanning random ports.

Clarify networking basics by explaining ports, how to measure them, and how to use the network manager, while identifying device names on your Linux system.

Inspect and manage Linux network interfaces, identifying loopback and broadcast-capable cards like wifi and ethernet. Bring interfaces up, obtain IPs, and test reachability to sites such as archlinux.org.

Use sudo iftop to monitor traffic on a selected interface, observe dns queries via pie hole, and review port activity and ssh login attempts for security awareness.

Compare TCP and UDP by examining reliability in video calls and streaming, then explain how SSH maintains ordered keystrokes even on slow networks.

Master iptables as a versatile firewall that filters network traffic, using icmp echo request rules to reject or drop. Learn to list, add, and manage rules, often via ufw.

Understand how network address translation preserves private intranet by mapping internal 192.168.x.x and 10.x.x.x addresses to a shared external IP, and why IPv6 solves IPv4 exhaustion.

Explore how network manager streamlines wifi and ethernet connections, replacing manual WPA supplicant workflows, by automatically scanning networks, obtaining IP addresses, and managing service states.

Learn how being behind a NAT or double NAT affects port forwarding and access. Check your router versus public IPv4 addresses, and consider remote hosting when NAT blocks direct access.

Master basic advanced networking concepts, identify active devices (Wi-Fi, Ethernet) and monitor traffic and incoming connections. Learn iptables in theory, draft simple rules, and check network manager and NAT behavior.

Discover why automated backups matter and how to simply copy your important files to a different location using available tools.

Practice backing up files by generating fortune text, organizing into cow-named directories, archiving into a single file, and transferring with scp to compare transfer times.

Create tar archives and compress them with gzip to produce tar.gz, then extract on another computer to verify identical directories; explore tar variants and practical backup scripts.

Learn rsync, a flexible backup tool that copies entire directory structures to remote servers efficiently, with options for recursive copying, progress display, and avoiding overwriting newer files.

Learn to use the dd command for exact data duplication and disk imaging, with careful input and output targets like /dev/sdb and its partitions for a backup image.

Learn the fundamentals of backups: transfer one big file using tar, handle variants, install and unzip tools like BSDs, keep your data in sync, and copy entire disks with dd.

Examine the kernel's module system and toggle modules, querying their information. Trace the boot sequence from startup to loading the kernel and reach runlevels enabling root login, users, and networking.

Learn how the Linux kernel acts as the driver layer for CPU, disk, and memory, and how kernel versions enable mounting NTFS Windows partitions.

Explore how to manage kernel modules with modprobe, disable the PC speaker by blacklisting the module, and apply changes without reboot.

The lecture outlines the startup sequence from BIOS to the master boot record and kernel, then explains run levels, EFI, and GPT, with grub and systemd referenced.

Explore Linux run levels from 0 halt to 6 reboot, highlighting single-user mode with root access and how network services and daemons start during boot on debian-based systems.

Explore the Linux startup sequence, from kernel and module management with Grub, to run levels from single-user mode to multi-user networks, plus recovery and distro variations.

Take a hands-on tour from compiling your own kernel to understanding systemd and service behavior, then explore System Rescue for booting with minimal system components when things go wrong.

Compile a customized Linux kernel from kernel.org or GitHub, configure with make menuconfig, build with make, install modules, copy to boot, update grub, reboot, and verify the new kernel.

Discover how systemd manages services with unit files, restarts failed processes, and uses systemctl and journalctl to start, stop, enable, disable, and monitor.

Learn to create a minimal systemd unit file for a simple 'cows' service, manage its startup with ExecStart and Restart, reload the daemon, and observe the output every 3 seconds.

Learn to rescue a nonfunctional Linux system using virtual terminals and rescue mode. Switch between virtual terminals, edit boot options, and perform maintenance like disabling services to restore functionality.

Explore disk partitioning and file types, starting with theory on what partitioning is and why it matters, then review commands to divide multiple disks and optimize for different file types.

Explore basic disk theory with a library-card analogy, covering partition tables, start-of-disk metadata, and why deletions affect entries rather than erase data.

Learn manual disk partitioning by creating a boot partition, a root partition (with ZFS option), a home partition, and swap, with proper bootable settings and safety through journaling.

Inspect partitions and verify filesystem layout with standard commands, confirming home on an extended filesystem, boot on its partition, and root on ZFS.

Choose the net installer for deploying Linux across multiple machines, performing a minimal install and updating from the internet; ISO downloads are large and slower for one.

Learn to create and manage partitions with fdisk on a new disk, make a filesystem on /dev/sdb1, and mount it at a chosen mount point like /zfs, including fstab considerations.

Explore Linux file systems and partition types, noting primary vs logical partitions, ext4 and ext2 as Linux native options, and prefer parted or fdisk over GUI tools such as GParted.

Explore raid concepts by showing how writing data to two disks at the same time can boost speed, using raid zero and various configurations.

Explore the basic theory of raid zero, showing how splitting data across two disks speeds up writes by distributing information and how to set up raid zero.

Simulate raid 0 with multiple disks using virtualization, install mdadm and zfs tools, create a two-disk md array, format with zfs, mount it, and evaluate performance.

Explain raid one's disk mirroring that copies data across two disks to protect against disk failure, contrast with raid zero's striping, and note its speed limits and backup limitations.

Explore raid 5, using parity across multiple disks to recover from a single disk failure, while delivering fast performance and raid one style safety.

Replace the damaged disk in a degraded raid five array by adding a new disk, then let mdadm rebuild and monitor /proc/mdstat to verify recovery, all while maintaining backups.

Explain the basic concepts of software raid and hardware raid, including RAID 0, 1, 5, and 6, and differences in BIOS and server implementations.

Compare raid 0, 1, 5: raid 0 is fast but unsafe; raid 1 is dependable with no speed gain; raid 5 improves performance while protecting data; software, hardware options exist.