Linux administration for operations

Objectives and progression

Twelve modules teach how to observe a Linux system, form hypotheses, and choose justified interventions. Lessons connect systemd, identity, storage, performance, networking, Bash, resource isolation, data publication, and recovery to production-support tasks. Each module includes its own questions; twenty fictional cases show constraints, consequences, and alternative decisions. The final assessment reuses path questions to consolidate learning. References identify versions and context differences: SELinux examples use RHEL 10 and do not represent every distribution.

Audience: L2/L3 support professionals, administrators, and technical managers coordinating Linux services.

Prerequisites: Familiarity with a terminal, files, and IT services. Hands-on exercises should use an authorized environment.

470 estimated study minutes

• Collect bounded evidence and distinguish symptoms from causes.
• Relate service state, permissions, and resources to functional impact.
• Interpret networking and script failures without overlooking execution context.
• Plan changes and recovery with validation, persistence, and partial-data handling.

Modules

1. Start with context and preserve evidence
2. Interpret services and logs with systemd
3. Diagnose identity, permissions, and SELinux
4. Distinguish space, inodes, and mounts
5. Interpret CPU, memory, and I/O waiting
6. Separate DNS, connections, TLS, and the application
7. Shell: arguments, pipelines, and exit codes
8. Maintenance and demonstrated recovery
9. Isolate resources and establish readiness on Linux
10. Recover filesystems and publish data safely
11. Diagnose networking in the application context
12. Automate with Bash: failures, concurrency, and delivery

Continue learning

Technical assessments

• SSH
• DNS
• Production Support L3

References and version

DR Linux 2026.4; networking and Bash manuals reviewed 2026-10-01; cgroup v2 and upstream systemd manuals reviewed 2026-10-01; RHEL 10 examples; Linux man-pages 6.19; OpenSSL 3.5

• RHEL 10: system status and performance · 2026-09-29
• systemctl(1): system and service manager · 2026-09-29
• journalctl(1): query the journal · 2026-09-29
• path_resolution(7): path traversal · 2026-09-29
• unlink(2): remove a directory entry · 2026-09-29
• RHEL 10: troubleshooting SELinux · 2026-09-29
• Linux cgroup v2 administration · 2026-09-29
• proc_loadavg(5): Linux load average · 2026-09-29
• proc_meminfo(5): memory information · 2026-09-29
• ss(8): socket statistics · 2026-09-29
• getent(1): name service databases · 2026-09-29
• bash(1): shell expansion and pipelines · 2026-09-29
• df(1): filesystem space · 2026-09-29
• fstab(5): filesystem table · 2026-09-29
• OpenSSL s_client diagnostics · 2026-09-29
• systemd.resource-control(5) · 2026-10-01
• systemd.service(5) · 2026-10-01
• systemd.unit(5) · 2026-10-01
• Control Group v2 · 2026-10-01
• PSI: Pressure Stall Information · 2026-10-01
• findmnt(8) · 2026-10-01
• mount_namespaces(7) · 2026-10-01
• rename(2) · 2026-10-01
• fsync(2) · 2026-10-01
• e2fsck(8) · 2026-10-01
• xfs_repair(8) · 2026-10-01
• acl(5) · 2026-10-01
• du(1) · 2026-10-01
• Contingency Planning Guide for Federal Information Systems · 2026-10-01
• ip-route(8) · 2026-10-01
• ip-rule(8) · 2026-10-01
• ip-netns(8) · 2026-10-01
• ss(8) · 2026-10-01
• bash(1) · 2026-10-01
• flock(1) · 2026-10-01
• timeout(1) · 2026-10-01
• mktemp(1) · 2026-10-01
• connect(2) · 2026-10-01
• ip(7) · 2026-10-01
• getent(1) · 2026-10-01
• curl manual · 2026-10-01
• flock(2) · 2026-10-01
• find(1) · 2026-10-01
• IPV6_V6ONLY(2const) · 2026-10-01
• openssl-s_client · 2026-10-01