Backup Recovery

Common Problems 115626

firewalld Runtime Rules Lost After Reboot

🟡 Medium   ⏱ 5–30 min  Last verified: 4 December 2020 📖 ~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 113607

Windows Server 2012 R2 — WSUS Synchronization Stalls and New Security Updates Never Appear — Fix & Prevention

🟠 High   ⏱ 5–30 min  Last verified: 4 December 2020 Affected versions: Windows Server 2012 R2 📖 ~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 Upgrade Oracle Linux 7 to Oracle Linux 8 — step-by-step Oracle Linux 8 tutorial on Progressive Robot

How to Upgrade Oracle Linux 7 to Oracle Linux 8

Introduction Setting up upgrade oracle linux 7 to oracle linux 8 on a Oracle Linux 8 server is a common task for system administrators, DevOps engineers, and site reliability engineers. This guide explains how to Upgrade Oracle Linux 7 to Oracle Linux 8, with all the commands you need, the SELinux and firewalld considerations to […]

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Common Problems 118389

Ubuntu 16.04 LTS – apt update fails with NO_PUBKEY for third-party repository – Fix & Prevention

🟠 High   ⏱ 5–30 min  Last verified: 3 December 2020 Affected versions: Ubuntu 16.04 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 115095

RHEL 8 Postfix Mail Delivery Blocked by Firewall and SELinux

🟡 Medium   ⏱ 5–30 min  Last verified: 3 December 2020 📖 ~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 115045

RHEL 8 journalctl Storage Growth Consumes Root Disk

🟡 Medium   ⏱ 5–30 min  Last verified: 3 December 2020 📖 ~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 112993

Windows Server 2016 — Server (LanmanServer) service refuses connections — Fix & Prevention

🟠 High   ⏱ 5–30 min  Last verified: 3 December 2020 Affected versions: Windows Server 2016 📖 ~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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How to Configure Fail2ban on Oracle Linux 8 — step-by-step Oracle Linux 8 tutorial on Progressive Robot

How to Configure Fail2ban on Oracle Linux 8

Introduction This tutorial demonstrates how to Configure Fail2ban 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 AppStream […]

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Common Problems 117418

Ubuntu 20.04 LTS – apt update shows NO_PUBKEY for repository signatures

🟠 High   ⏱ 5–30 min  Last verified: 2 December 2020 Affected versions: Ubuntu 20.04 LTS Ubuntu 20.04 Ubuntu 20.04.6 📖 ~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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How to Configure Oracle Linux 8 with FCoE Storage — step-by-step Oracle Linux 8 tutorial on Progressive Robot

How to Configure Oracle Linux 8 with FCoE Storage

Introduction This tutorial demonstrates how to Configure Oracle Linux 8 with FCoE Storage 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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