Check Linux CPU, memory, and disk pressure
Collect time-stamped capacity and pressure data before restarting services or resizing a host.
Read guide →LEARNING PATH · BEGINNER–INTERMEDIATE
Linux Troubleshooting and Operations
For learners who can use a shell and want a repeatable approach to host issues.
Prerequisites
Basic command-line familiarity and authorized read access.
Learning objectives
- Collect evidence before restarts.
- Separate resource, filesystem, DNS, and connectivity symptoms.
- Verify and communicate a safe remediation.
Follow these lessons
Troubleshoot a Linux service that fails to start
Collect unit state and logs before retrying a failed service; isolate configuration, permissions, dependencies, and port conflicts.
Read guide →Troubleshoot a Linux server running out of disk space
Determine whether bytes or inodes are exhausted, locate the affected mount, and reclaim data through its owning application.
Read guide →Troubleshoot SSH connection refused on Linux
Trace hostname, route, destination port, listener, and firewall path to find where an SSH connection is rejected.
Read guide →Troubleshoot DNS resolution failures
Compare system lookups with direct resolver answers to isolate local configuration, upstream reachability, and record problems.
Read guide →Troubleshoot Linux firewall access safely
Confirm the service listener, active firewall manager, source path, and effective policy before a narrow rules change.
Read guide →
Official documentation
Practice and next steps
Keep an incident notebook; consider LFCS preparation after gaining hands-on experience.
Explore the hands-on lab directory and official training recommendations. Certification exams require separate registration and passing the applicable exam.