linux-rhel

What problem does it solve?

Provide concise, actionable guidance for Red Hat Enterprise Linux system administration and troubleshooting so operators can quickly recover services, expand storage, resolve SELinux denials, configure networking, and investigate performance or crashes without searching multiple sources.

Core Features & Use Cases

• Service and boot troubleshooting: systemd unit inspection, journal analysis, default targets, and recovery steps for failing services.
• Storage and LVM management: pv/vg/lv creation, extending volumes, pvmove workflows, snapshots, and filesystem growth procedures.
• Security and policy: SELinux diagnosis and policy module creation, auditd monitoring, PAM/authselect guidance, and FIPS considerations.
• Networking and firewall: nmcli connection management, bonding/VLAN configuration, and firewalld rule and zone administration.
• Package, performance, and crash analysis: dnf/rpm history and rollbacks, tuned profiles, perf/sar/iostat diagnostics, kdump enablement and vmcore analysis.
• Use Case: Recover a production web service that fails due to SELinux AVC denials by identifying denials, generating a policy module, restoring contexts, and verifying service startup.

Quick Start

Diagnose why my application service fails to start by listing the unit status, recent journalctl errors, SELinux AVC denials, and any related file context or permission issues and provide step‑by‑step remediation.