RHEL 9

How to Install Graylog for Centralised Log Management on RHEL 9 — step-by-step RHEL 9 tutorial on Progressive Robot

How to Install Graylog for Centralised Log Management on RHEL 9

Graylog is an open-source centralised log management platform that collects, indexes, and analyses log data from across your infrastructure in one place. On RHEL 9, deploying Graylog 5.x gives operations teams powerful search, alerting, and dashboarding capabilities without relying on cloud-based log services. Graylog depends on MongoDB for metadata storage and OpenSearch (or Elasticsearch) for […]

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How to Use OpenSSL to Generate and Manage SSL Certificates on RHEL 9 — step-by-step RHEL 9 tutorial on Progressive Robot

How to Use OpenSSL to Generate and Manage SSL Certificates on RHEL 9

OpenSSL is the most widely used toolkit for working with SSL/TLS certificates on Linux systems. On RHEL 9, it provides everything you need to generate private keys, create certificate signing requests (CSRs), sign certificates using your own certificate authority, and convert between certificate formats. Understanding OpenSSL is essential for any sysadmin managing secure services. This […]

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Common Problems 114609

FIPS Mode Enablement Causes Boot Or Crypto Failures

🟡 Medium   ⏱ 5–30 min  Last verified: 4 April 2024 📖 ~1 min read Table of contents Symptom & Impact Environment & Reproduction Root Cause Analysis Quick Triage Step-by-Step Diagnosis Solution – Primary Fix Solution – Alternative Approaches Verification & Acceptance Criteria Rollback Plan Prevention & Hardening Related Errors & Cross-Refs References & Further […]

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Common Problems 114454

firewalld Blocks Required Application Port

🟡 Medium   ⏱ 5–30 min  Last verified: 31 March 2024 📖 ~1 min read Table of contents Symptom & Impact Environment & Reproduction Root Cause Analysis Quick Triage Step-by-Step Diagnosis Solution – Primary Fix Solution – Alternative Approaches Verification & Acceptance Criteria Rollback Plan Prevention & Hardening Related Errors & Cross-Refs References & Further […]

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How to Use Docker Volumes and Bind Mounts on RHEL 9 — step-by-step RHEL 9 tutorial on Progressive Robot

How to Use Docker Volumes and Bind Mounts on RHEL 9

Docker containers are ephemeral by default — all data written inside a container is lost when the container is removed. Docker provides two mechanisms for persisting data and sharing files between containers and the host: volumes (managed by Docker, stored in /var/lib/docker/volumes/) and bind mounts (map a host directory directly into a container). Volumes are […]

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How to Install and Use Podman with systemd Socket Activation on RHEL 9 — step-by-step RHEL 9 tutorial on Progressive Robot

How to Install and Use Podman with systemd Socket Activation on RHEL 9

Podman is RHEL 9’s default container engine and, unlike Docker, runs entirely rootless and integrates natively with systemd. Socket activation is a systemd feature that lets the kernel hold a listening socket open while the service is stopped; the moment the first connection arrives, systemd starts the corresponding service and hands the socket over. This […]

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Common Problems 114602

SELinux Boolean Not Persisting Across Reboot

🟡 Medium   ⏱ 5–30 min  Last verified: 19 March 2024 📖 ~1 min read Table of contents Symptom & Impact Environment & Reproduction Root Cause Analysis Quick Triage Step-by-Step Diagnosis Solution – Primary Fix Solution – Alternative Approaches Verification & Acceptance Criteria Rollback Plan Prevention & Hardening Related Errors & Cross-Refs References & Further […]

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Common Problems 114532

RHEL 9 NetworkManager Profile Applies Wrong DNS Settings

🟡 Medium   ⏱ 5–30 min  Last verified: 15 March 2024 📖 ~1 min read Table of contents Symptom & Impact Environment & Reproduction Root Cause Analysis Quick Triage Step-by-Step Diagnosis Solution – Primary Fix Solution – Alternative Approaches Verification & Acceptance Criteria Rollback Plan Prevention & Hardening Related Errors & Cross-Refs References & Further […]

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How to Install and Configure cAdvisor for Container Monitoring on RHEL 9 — step-by-step RHEL 9 tutorial on Progressive Robot

How to Install and Configure cAdvisor for Container Monitoring on RHEL 9

cAdvisor (Container Advisor) is an open-source daemon from Google that collects, aggregates, and exposes resource usage and performance metrics for every running container on a host. Unlike Docker’s built-in docker stats, cAdvisor exposes its data in Prometheus format, making it a natural fit for scraping alongside Node Exporter. This tutorial covers running cAdvisor on RHEL […]

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Common Problems 114475

RHEL 9: NFS Mount Permission Denied

🟡 Medium   ⏱ 5–30 min  Last verified: 9 March 2024 📖 ~1 min read Table of contents Symptom & Impact Environment & Reproduction Root Cause Analysis Quick Triage Step-by-Step Diagnosis Solution – Primary Fix Solution – Alternative Approaches Verification & Acceptance Criteria Rollback Plan Prevention & Hardening Related Errors & Cross-Refs References & Further […]

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