Troubleshooting

Common Problems 121633

Debian 9: Fail2ban blocks internal monitoring IPs

🟡 Medium   ⏱ 5–30 min  Last verified: 26 January 2021 Affected versions: Debian 9 📖 ~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 & […]

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Common Problems 118930

Ubuntu 14.04 LTS – dist-upgrade aborts with held broken packages

🟠 High   ⏱ 5–30 min  Last verified: 26 January 2021 Affected versions: Ubuntu 14.04 LTS Ubuntu 14.04 Ubuntu 14.04.6 📖 ~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 […]

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Common Problems 117521

Ubuntu 20.04 LTS – systemd service fails with status=203/EXEC – Fix & Prevention

🟠 High   ⏱ 5–30 min  Last verified: 26 January 2021 Affected versions: Ubuntu 20.04 LTS 📖 ~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 […]

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Alpine Linux edge — zstd — multiple vulnerabilities (3 CVEs) — patch and remediation guide — diagnosis and fix on Alpine Linux edge

Alpine Linux edge — zstd — multiple vulnerabilities (3 CVEs) — patch and remediation guide

🟡 Medium   ⏱ 10–30 min  Last verified: 25 May 2026 Affected versions: Alpine Linux edge / fixed in 1.4.9-r0 📖 ~4 min read  •  Source: Alpine secdb entry — zstd 1.4.9-r0 Related CVEs: CVE-2021-24032 CVE-2021-24031 CVE-2019-11922 Upstream summary: Alpine main repository for vedge ships zstd 1.4.9-r0 which addresses CVE-2021-24032. Table of contents Symptom & […]

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How to Set Up NFS on Oracle Linux 8 — step-by-step Oracle Linux 8 tutorial on Progressive Robot

How to Set Up NFS on Oracle Linux 8

Introduction This tutorial demonstrates how to Set Up NFS on Oracle Linux 8 on Oracle Linux 8. It is written for administrators who want a repeatable, well-explained walkthrough that goes beyond a bare command list and explains each configuration choice. Every command is tested against a freshly registered Oracle Linux 8 system with the default […]

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How to Install Prometheus and Grafana on RHEL 8 — step-by-step RHEL 8 tutorial on Progressive Robot

How to Install Prometheus and Grafana on RHEL 8

Prometheus and Grafana are two of the most widely adopted open-source tools for infrastructure monitoring and metrics visualization. Prometheus scrapes and stores time-series data from your systems, while Grafana turns that data into rich, interactive dashboards. Together they give RHEL 8 administrators a powerful, production-ready observability stack. This tutorial walks through installing both tools from […]

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Oracle Linux 8 — python36:3.6 — vulnerability — patch and remediation guide — diagnosis and fix on Oracle Linux 8

Oracle Linux 8 — python36:3.6 — vulnerability — patch and remediation guide (ELSA-2021-9129)

🟠 High   ⏱ 15–60 min  Last verified: 26 January 2021 Affected versions: Oracle Linux 8 📖 ~4 min read  •  Source: ELSA advisory ELSA-2021-9129 Related CVEs: CVE-2021-3177 Table of contents Symptom & Impact Environment & Reproduction Root Cause Analysis Quick Triage Step-by-Step Diagnosis Solution – Primary Fix Solution – Alternative Approaches Verification & Acceptance […]

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Oracle Linux 8 — Unbreakable Enterprise kernel — vulnerability — patch and remediation guide — diagnosis and fix on Oracle Linux 8

Oracle Linux 8 — Unbreakable Enterprise kernel — vulnerability — patch and remediation guide (ELSA-2020-5805)

🟠 High   ⏱ 15–60 min  Last verified: 26 January 2021 Affected versions: Oracle Linux 8 📖 ~4 min read  •  Source: ELSA advisory ELSA-2020-5805 Related CVEs: CVE-2019-19054 CVE-2019-19462 CVE-2020-10768 CVE-2020-10767 CVE-2020-10732 CVE-2020-12888 Table of contents Symptom & Impact Environment & Reproduction Root Cause Analysis Quick Triage Step-by-Step Diagnosis Solution – Primary Fix Solution – […]

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