1.1 Overview and Certifications

The Linux Ecosystem

Linux is a free, open-source operating system kernel created by Linus Torvalds in 1991. Today, “Linux” typically refers to the kernel plus a collection of GNU utilties and software, forming a variety of “distributions” (distros).

Key Distribution Families

For a system administrator, understanding the two main corporate lineages is crucial:

1. Debian Family:

   • Debian: The upstream, stable, community-driven project.
   • Ubuntu: Based on Debian, highly popular in cloud and enterprise. Uses .deb packages and the apt manager.
   • Linux Mint/Kali/Pop!_OS: Other derivatives.

2. Red Hat Family (RHEL):

   • Red Hat Enterprise Linux (RHEL): The commercial standard.
   • Fedora: The upstream testing ground for RHEL.
   • Rocky Linux / AlmaLinux: Community-driven, binary-compatible alternatives to RHEL (filling the void left by CentOS). Uses .rpm packages and the dnf/yum manager.

Official Certifications

Validating your skills is essential for career progression. This course targets the following:

Linux Foundation Certified Sysadmin (LFCS)

• Focus: Practical, hands-on ability to design, install, configure, and manage a system.
• Vendor: The Linux Foundation (neutral).
• Exam Format: 100% Performance-based (Live terminal). You are given tasks to solve.
• Distributions: You effectively choose between Ubuntu and Rocky/CentOS stream.

Red Hat Certified System Administrator (RHCSA)

• Focus: Core system administration skills in Red Hat environments.
• Vendor: Red Hat.
• Exam Format: 100% Performance-based (EX200).
• Distributions: RHEL.

Why performance-based?

Multiple-choice exams are rare in Linux admin. You must know how to do the task, not just remember the theory. Muscle memory is key.