CompTIA Linux+ is the Linux world's “all-in-one” certification: a single exam, vendor-neutral, covering modern administration — from the classic terminal to containers, Git, and automation. For anyone who already has other CompTIA certifications (A+, Network+, Security+) or wants a single credential instead of a series of exams, it is the natural choice. This post closes our Linux certification series — see also LPIC-1, LFCS and RHCSA.
How the exam works
As of publication, the current version is XK0-005: a maximum of 90 questions in 90 minutes, mixing multiple-choice questions with simulated practical questions (performance-based, where you operate an environment). Around ~12 months of Linux experience is recommended, but there is no formal prerequisite. The certification is valid for 3 years and can be renewed through the continuing education (CE) program from CompTIA — without retaking the exam, by earning credits. Check the available language and version when scheduling; the exam is usually delivered in English.
The exam's four domains
- System management (~32%): boot, packages from both families, storage and LVM, processes, systemd services, networking, virtualization — the sysadmin's daily work;
- Troubleshooting (~28%): the second-largest share — diagnosing networking, permissions, storage, CPU/memory performance, and service failures; the exam loves a broken scenario for you to fix;
- Security (~21%): permissions and ACLs, SELinux/AppArmor, PAM, hardened SSH, firewalls, certificates, and best practices;
- Scripting, containers, and automation (~19%): what sets Linux+ apart — shell scripting, Git, containers, basic orchestration, and infrastructure-as-code concepts.
How to train
Linux+ punishes rote memorization: the practical questions require diagnosis. Practice breaking and fixing things — instead of just configuring a service, sabotage it and fix it:
# treino de troubleshooting: por que o serviço não sobe?
systemctl status nginx --no-pager # estado e último erro
journalctl -u nginx -n 20 --no-pager # o log conta a história
ss -tlnp | grep :80 # a porta já está ocupada?
ls -lZ /var/www/html | head # contexto SELinux correto?
df -h && free -m # disco cheio? memória?
Add the modern trio that other exams emphasize less: a real Git repository for your scripts, containers in your daily work, and shell scripts for every repetitive task. The detailed official objectives are on CompTIA's website — use them as a checklist.
Where to start
Before targeting any exam, the foundation is the same: terminal fluency, packages, permissions, processes, networking, and shell scripting. That is exactly the path offered by Linux course by Gabriel (Toca do Tux), in Portuguese and starting with migration. With a solid foundation, choose your exam: Linux+ if you want breadth in a single exam, LPIC-1 or LFCS if you prefer the classic path, RHCSA if your target is the corporate Red Hat world.
Certification does not replace experience — but it opens the door to gaining it. Choose one, build your lab, and start today. 🐧