September 2020 - Page 32 of 66

Common Problems 118125

Ubuntu 18.04 LTS – Certbot renewal fails because port 80 is in use – Fix & Prevention

🟡 Medium   ⏱ 5–30 min  Last verified: 20 May 2026 Affected versions: Ubuntu 18.04 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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Common Problems 114522

RHEL 9 DNF Update Fails with GPG Signature Errors

🟡 Medium   ⏱ 5–30 min  Last verified: 19 May 2026 📖 ~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 114014

RHEL 10 – NFS Mount Throws Stale File Handle During Workloads – Stabilization Steps

🟠 High   ⏱ 5–30 min  Last verified: 19 May 2026 Affected versions: RHEL 10.0 RHEL 10.1 📖 ~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 […]

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How to Set Up ClamAV Antivirus on SLES 15 — step-by-step SUSE Linux Enterprise 15 tutorial on Progressive Robot

How to Set Up ClamAV Antivirus on SLES 15

Introduction This tutorial covers How to Set Up ClamAV Antivirus on SLES 15 on SLES 15. SLES 15 (SUSE Linux Enterprise Server 16) is SUSE’s enterprise-grade Linux distribution. It uses the zypper package manager, AppArmor for mandatory access control, and systemctl for service management. Prerequisites Ensure your SLES 15 system is up to date: zypper […]

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How To Use a PostgreSQL Database in a Flask Application — step-by-step Databases tutorial on Progressive Robot

How To Use a PostgreSQL Database in a Flask Application

In web applications, you usually need a database, which is an organized collection of data. You use a database to store and maintain persistent data that can be retrieved and manipulated efficiently. PostgreSQL, or Postgres, is a relational database management system that provides an implementation of the SQL querying language. In this tutorial, you’ll build a small book review web application that demonstrates how to use the psycopg2 library, a PostgreSQL database adapter.

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Ubuntu 16.04 — slirp — multiple vulnerabilities (2 CVEs) — patch and remediation guide — diagnosis and fix on Ubuntu 16.04

Ubuntu 16.04 — slirp — multiple vulnerabilities (2 CVEs) — patch and remediation guide

🟢 Low   ⏱ 5–15 min  Last verified: 25 May 2026 Affected versions: Ubuntu 16.04 (xenial) 📖 ~4 min read  •  Source: Ubuntu Security Notice USN-4632-1 Related CVEs: CVE-2020-7039 CVE-2020-8608 Upstream summary: It was discovered that the SLiRP networking implementation of the QEMU emulator did not properly manage memory under certain circumstances. An attacker could […]

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Oracle Linux 8 — binutils — vulnerability — patch and remediation guide — diagnosis and fix on Oracle Linux 8

Oracle Linux 8 — binutils — vulnerability — patch and remediation guide (ELSA-2024-9689)

🟢 Low   ⏱ 5–15 min  Last verified: 25 May 2026 Affected versions: Oracle Linux 8 📖 ~4 min read  •  Source: ELSA advisory ELSA-2024-9689 Related CVEs: CVE-2018-12699 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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