DNS

Oracle Linux 9 — jackson-annotations, jackson-core, jackson-databind, jackson-jaxrs-providers, and jackson-modules-base — vulnerability — p… (ELSA-2025-12280)

• April 4, 2023
• Linux
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🟠 High   ⏱ 15–60 min  Last verified: 4 April 2023 Affected versions: Oracle Linux 9 📖 ~4 min read  •  Source: ELSA advisory ELSA-2025-12280 Related CVEs: CVE-2025-52999 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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Ubuntu 20.04 LTS – high CPU from kswapd0 due to memory pressure

• April 4, 2023
• Linux
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🟠 High   ⏱ 5–30 min  Last verified: 4 April 2023 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 Redis Sentinel on Oracle Linux 9

• April 4, 2023
• Oracle Linux
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Introduction This tutorial demonstrates how to Configure Redis Sentinel on Oracle Linux 9 on Oracle Linux 9. 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 9 system with the default […]

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Windows Server 2022 DHCP Failover Partner State Stuck in Communication Interrupted – Fix & Prevention

• April 4, 2023
• Tutorials
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🟠 High   ⏱ 5–30 min  Last verified: 4 April 2023 Affected versions: Windows Server 2022 📖 ~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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NetworkManager Connected but No Internet Access

• April 3, 2023
• Tutorials
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🟡 Medium   ⏱ 5–30 min  Last verified: 3 April 2023 📖 ~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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Windows Server 2022 — FSRM quota notifications stop firing on volume thresholds — Fix & Prevention

• April 3, 2023
• Tutorials
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🟡 Medium   ⏱ 5–30 min  Last verified: 3 April 2023 Affected versions: Windows Server 2022 📖 ~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 Set Up Remote Desktop Services on Windows Server 2022

• April 3, 2023
• Tutorials
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How to Set Up Windows Server 2022 Core (Minimal Installation) Windows Server Core is a lean installation option that omits the Explorer shell, the Start menu, and most graphical management tools. The result is a server with a dramatically reduced attack surface, lower memory footprint, fewer patches required per month, and — critically — fewer […]

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How to Monitor MySQL with Percona Monitoring and Management on RHEL 8

• April 3, 2023
• Linux
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Percona Monitoring and Management (PMM) is an open-source platform that provides deep visibility into MySQL, MariaDB, PostgreSQL, and MongoDB performance — including query analytics, slow-query identification, and time-series dashboards — without requiring a commercial licence. Running PMM Server as a Docker container keeps the server component isolated and easy to upgrade, while the lightweight PMM […]

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Inode Exhaustion on /var Breaking Package and Log Writes

• April 2, 2023
• Tutorials
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🟡 Medium   ⏱ 5–30 min  Last verified: 2 April 2023 📖 ~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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Windows Server 2022 – DFSR SYSVOL backlog remains high after domain controller restart – Fix & Prevention

• April 2, 2023
• Tutorials
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🟠 High   ⏱ 5–30 min  Last verified: 2 April 2023 Affected versions: Windows Server 2022 📖 ~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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