RH342: Red Hat Enterprise Linux Diagnostics and Troubleshooting — Lesson 4: Kernel, Memory, CPU, Performance, Root Cause, and Prevention

Learning Objectives

• Explain the structures, services, data, settings, roles, and dependencies governing kernel analysis and memory pressure.
• Implement and validate CPU and I/O, performance tools, and root-cause documentation using reviewable evidence.
• Evaluate the condition where a technically valid implementation creates operational risk because ownership, monitoring, rollback, or handover controls are incomplete and select a proportionate corrective response.

Detailed Topics

• kernel analysis applied to the course scenario, expected platform behavior, dependencies, controls, and evidence.
• memory pressure applied to the course scenario, expected platform behavior, dependencies, controls, and evidence.
• CPU and I/O applied to the course scenario, expected platform behavior, dependencies, controls, and evidence.
• performance tools applied to the course scenario, expected platform behavior, dependencies, controls, and evidence.
• root-cause documentation applied to the course scenario, expected platform behavior, dependencies, controls, and evidence.

Instructor Demonstration

The instructor traces a senior Linux support team resolving recurring production incidents with a consistent diagnostic methodology. The walkthrough connects navigation, commands, configuration logic, system messages, and evidence captured in the RHEL diagnostic workflow, incident evidence pack, root-cause report, and preventive action register. It also tests the exception where a technically valid implementation creates operational risk because ownership, monitoring, rollback, or handover controls are incomplete.

Hands-On Exercise

Complete a controlled Red Hat exercise covering Kernel, Memory, CPU, Performance, Root Cause, and Prevention and preserve the verified result in the RHEL diagnostic workflow, incident evidence pack, root-cause report, and preventive action register.

1. Confirm scope, prerequisites, versions, identities, dependencies, and acceptance criteria.
2. Execute the workflow while recording commands, settings, outputs, events, and system messages.
3. Test normal behavior, one boundary condition, and the stated exception.
4. Document corrections, evidence, ownership, retest criteria, rollback, and handover actions.

Scenario Analysis

• Identify which object, service, policy, setting, or sequence most strongly influences kernel analysis.
• Compare two defensible responses and explain technical, security, operational, and support trade-offs.
• Determine how the RHEL diagnostic workflow, incident evidence pack, root-cause report, and preventive action register should be approved, retained, retested, and updated.

Troubleshooting Guidance

Start where expected behavior first differs from the observed result. Check prerequisites, identity, configuration order, version compatibility, connectivity, status, resource limits, and evidence separately. Treat “a technically valid implementation creates operational risk because ownership, monitoring, rollback, or handover controls are incomplete” as a hypothesis until commands, logs, settings, and retest outcomes confirm the cause.

Validation Checklist

• Required platform components, identities, permissions, settings, and dependencies are present.
• The RHEL diagnostic workflow, incident evidence pack, root-cause report, and preventive action register connects each conclusion to objective, reviewable evidence.
• Normal processing, a boundary condition, dependency behavior, and the stated exception were tested.
• Corrections, ownership, retest criteria, rollback, documentation, and operational handover are complete.

Lesson Outcome

Learners can apply Kernel, Memory, CPU, Performance, Root Cause, and Prevention, explain the resulting platform behavior, and defend the outcome through the RHEL diagnostic workflow, incident evidence pack, root-cause report, and preventive action register.