Linux today and your career

Objective

See where Linux is used today, which jobs it opens up, which certifications count on a CV, and choose your path in this course: the Red Hat family or the Debian family.

Key points

• Linux runs the vast majority of web and cloud servers, 100% of the 500 most powerful supercomputers (since 2017), Android and a host of embedded devices.
• The main jobs: system administrator, DevOps engineer, SRE, cloud engineer, not forgetting security and embedded systems.
• The reference certifications: RHCSA then RHCE (Red Hat), LPIC-1 (LPI, vendor-neutral), LFCS (Linux Foundation).
• Choose one family to start with: Red Hat (large companies, banks, telecoms, public administrations) or Debian/Ubuntu (hosting providers, startups, cloud).
• About four fifths of what you will learn is common to both families: the core track of this course.

1. Where does Linux run?

Linux is the most widely used system in the world… even though few people see it. It is everywhere there is no Windows or macOS screen in front of you.

Remember this: when you check your bank account on your phone, it is very likely that Linux is present at every step: in the phone (Android), in the Internet box or the cell tower, in the bank's web server, and in its database.

2. Why Linux won

Going back over the six previous lessons, Linux's success can be summed up in five reasons:

1. It is free (lesson 0.3): no licence to pay per machine. For a hosting provider with 10,000 servers, that changes everything.
2. It is open: any company can adapt it to its hardware (Android, Internet boxes, supercomputers).
3. It follows the ideas of UNIX (lessons 0.1 and 0.2): solid, proven, and known to generations of engineers.
4. It is developed by everyone (lesson 0.4): competitors (Intel and AMD, Google and Microsoft) improve the same kernel together.
5. There are distributions for every need (lessons 0.5 and 0.6): RHEL for banking, Ubuntu for the cloud, Alpine for containers.

3. The jobs

Knowing how to administer Linux opens up several jobs, which often overlap. Job titles vary from one company to another.

A common career path: support technician or junior administrator → experienced system administrator → DevOps, SRE or cloud. In every case, the foundation is the same: being comfortable on the command line and understanding what is happening in a Linux system. That is exactly what this course builds.

In Morocco as elsewhere, there are many employers for Linux profiles: banks and insurance companies, telecom operators, public administrations, hosting providers, IT service companies and outsourcing centres (offshoring), startups.

4. The certifications

A certification proves to a recruiter that you know how to do things, not just that you have read about them. The main ones:

Hands-on exams (RHCSA, RHCE, LFCS) are often the most valued by recruiters: you cannot pass them by learning by heart. Certifications have a limited validity period (from two to five years depending on the organisation): check the current rules on the official website before registering, as they change regularly.

After a first Linux certification, many administrators move on to Kubernetes (CKA, from the Linux Foundation) or to the cloud providers' certifications (AWS, Azure, Google Cloud), all of which assume a good command of Linux.

5. Choosing your path: Red Hat family or Debian family?

This course offers a core track, then three tracks: Red Hat, Debian and Ubuntu. Here is how to choose.

The main differences you will come across:

The right advice: do not look for the "best" Linux. Learn one family thoroughly, then the differences of the other. An administrator who masters Rocky adapts to Ubuntu in a few days, and vice versa: the basic commands, systemd, SSH, permissions and the shell are the same.

6. How to progress

1. Practise every day, even for twenty minutes: system administration is learned with your fingers, not only with your eyes. Every lesson in this course has a lab for this.
2. Break things and fix them: in a lab, nothing is serious. Delete a file, stop a service, and work out how to undo it.
3. Read error messages all the way to the end: nine times out of ten, the solution is written there.
4. Learn to find documentation: man, --help, the official documentation of your distribution (core track, lesson on documentation).
5. Keep a notebook of your commands and solutions: it is the start of your own procedures, and a real asset in job interviews.
6. Aim for a certification: an exam date in your calendar is the best motivation.

7. The History module timeline

1964  Multics
1969  UNIX (Thompson, Ritchie, Bell Labs)
1973  UNIX rewritten in C; pipes
1978  BSD (Berkeley)
1983  System V (AT&T) — GNU Project (Stallman)
1985  Free Software Foundation
1988  POSIX
1989  GPL
1991  Linux 0.01 (Linus Torvalds)
1993  Slackware, Debian
1994  Linux 1.0; Red Hat Linux; SuSE
1998  "Open source"
2003  RHEL and Fedora
2004  Ubuntu; CentOS
2008  First Android phone
2017  Linux on 100% of TOP500 supercomputers
2019  IBM acquires Red Hat
2021  Rocky Linux and AlmaLinux
2024  End of CentOS 7
2025  RHEL 10, Debian 13
…     and what comes next is yours to write

Common misconceptions

• "Linux is for geeks, not for companies." It is the opposite: Linux is above all an enterprise system. It is on personal computers that it remains a minority.
• "With the cloud, Linux administrators are no longer needed." The cloud moves the work, it does not remove it: cloud virtual machines and containers are Linux systems that must be configured, secured and troubleshot.
• "You need to know how to program to administer Linux." Not to start with. Shell scripts come naturally with practice; a language such as Python becomes useful later, for DevOps or SRE.
• "A certification is enough to get hired." It opens doors, but the technical interview checks your practice: labs count as much as the diploma.

Lab

The last lab of the module, on Ubuntu 24.04:

grep '^VERSION_CODENAME=' /etc/os-release   # the code name of this version
uname -m                                    # the processor architecture

Note the code name and the architecture, then commit yourself: write the family you choose (redhat or debian) and the first certification you are aiming for. Nobody but you will read these files; it is a promise to yourself. Then click Check, and head to the core track.

Quiz

1. Name four fields where Linux is used, apart from desktop computers.
2. What is the main difference between a system administrator and an SRE?
3. Why is the RHCSA particularly valued by recruiters?
4. You want to work in a bank that uses RHEL. Which family do you learn first, and on which free distribution can you practise?
5. Name three differences between the Red Hat family and the Debian family.

Reference sources: TOP500 (top500.org), official certification pages of Red Hat, LPI and the Linux Foundation. Original MasterLinux text.