LFA case studies
LFA · Put your knowledge to work in context.
The Linux Foundation Certified IT Associate (LFCA) is an entry-level credential for people starting or formalizing a career in Linux-based IT. It suits help-desk staff, junior system administrators, cloud support engineers, and career changers who can already use a Linux desktop or server but want independent validation of the breadth expected in modern operations work. Rather than testing one tool deeply, the exam spans six areas: Linux fundamentals such as files, permissions, processes, and shell use; system administration basics including users, storage, services, networking, and backups; cloud computing concepts and service models; security fundamentals such as access control, encryption basics, and hardening; DevOps principles and tooling culture; and the practicalities of supporting applications and developers. Expect terminology-heavy, scenario-flavored multiple-choice items rather than deep debugging tasks. The LFA case studies are 5 cases and about 3,584 words.
1Nightly Backup Works by Hand but Not from Cron
Priya maintains a nightly backup job on an Ubuntu 22.04 server. The script is /home/priya/scripts/backup.sh, owned priya:priya with mode 750, and begins with #!/bin/bash.
688 words, about 3 min2Filesystem Reports Full While 59 GB of Space Remains
Monitoring pages the on-call engineer: the /var volume on an application server is at 100% and the PHP application is returning HTTP 500. The volume is 100 GB, formatted ext4, and supports online growth.
734 words, about 4 min3Instance Healthy After Reboot, Portal Unreachable
A team runs a small customer portal on one cloud VM (Ubuntu 22.04) with an automatically assigned public IPv4 address, not a reserved or static one. nginx terminates TLS on 443 and proxies to a Node.js process listening on 127.0.0.1:3000.
711 words, about 4 min4New Developer Cannot Use Public Key on a Hardened Bastion
An administrator is onboarding Sam, a new backend developer, to a RHEL 9 bastion host with SELinux in enforcing mode. sshd config contains PermitRootLogin no, PasswordAuthentication no, PubkeyAuthentication yes, and AllowUsers deploy admin.
723 words, about 4 min5Green Pipeline, Production Serves the Old Code
A four-person team ships a Node.js service through a CI/CD pipeline. The Dockerfile is FROM node:18 , then COPY .
728 words, about 4 min