Oracle Linux 8: System Administration II — Lesson 4: SELinux, Security, Performance, Ksplice, Troubleshooting, and Recovery

Learning Objectives

• Explain the purpose and operating context of SELinux contexts, booleans, policy diagnostics, and controlled exceptions.
• Apply sudo, PAM awareness, SSH hardening, auditing, and account controls and CPU, memory, disk, network, process, and journal-based diagnosis in a controlled environment.
• Validate outcomes and troubleshoot risks involving Ksplice awareness, kernel updates, rescue targets, rollback, and operations runbook.

Detailed Topics

• SELinux contexts, booleans, policy diagnostics, and controlled exceptions
• sudo, PAM awareness, SSH hardening, auditing, and account controls
• CPU, memory, disk, network, process, and journal-based diagnosis
• Ksplice awareness, kernel updates, rescue targets, rollback, and operations runbook

Instructor Demonstration

Demonstrate SELinux contexts, booleans, policy diagnostics, and controlled exceptions for an Oracle Linux server estate standardized, automated, secured, and recovered through storage, network, and service incidents; capture the exact configuration, code, command, transaction, query, dashboard, model, schedule, or report evidence that proves the expected result.

Hands-On Exercise

Complete a controlled Oracle Linux 8: System Administration II exercise covering sudo, PAM awareness, SSH hardening, auditing, and account controls and CPU, memory, disk, network, process, and journal-based diagnosis; introduce an exception involving Ksplice awareness, kernel updates, rescue targets, rollback, and operations runbook, diagnose it from evidence, apply the smallest reversible correction, and rerun acceptance checks.

1. Confirm scope, prerequisites, identities, dependencies, data, risks, and expected outcome.
2. Perform the course-specific configuration, development, administration, analysis, or business-process workflow.
3. Capture commands, settings, records, logs, screenshots, reports, metrics, or test results.
4. Compare the observed result with acceptance criteria and document corrective or preventive action.

Scenario Analysis

• Identify the technical or business decision and the stakeholders affected by it.
• Compare security, performance, reliability, compliance, cost, usability, and support trade-offs.
• Define rollback, recovery, communication, evidence, ownership, and escalation requirements.

Troubleshooting Guidance

Diagnose issues involving SELinux contexts, booleans, policy diagnostics, and controlled exceptions, sudo, PAM awareness, SSH hardening, auditing, and account controls, CPU, memory, disk, network, process, and journal-based diagnosis, Ksplice awareness, kernel updates, rescue targets, rollback, and operations runbook without making an unverified production change. Separate symptoms from causes, gather time-correlated evidence, test a reversible hypothesis, validate the correction, and record recurrence controls.

Validation Checklist

• The requirement, environment, inputs, dependencies, and expected result are documented.
• The result is reproducible and supported by product-specific evidence.
• Normal, boundary, failure, security, performance, and operational conditions are reviewed.
• Exceptions, rollback, ownership, support actions, and the next improvement priority are recorded.

Lesson Outcome

Learners can apply SELinux, Security, Performance, Ksplice, Troubleshooting, and Recovery in a realistic Oracle Linux 8: System Administration II scenario and defend the result with documented evidence.