DNS

Common Problems 112516

Windows Server 2019 — DHCP Server service refuses to start after scope conflict — Fix & Prevention

🟠 High   ⏱ 5–30 min  Last verified: 4 September 2023 Affected versions: Windows Server 2019 📖 ~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 […]

Read more
How to Install and Configure InfluxDB 2 on Debian 12 — step-by-step Debian 12 tutorial on Progressive Robot

How to Install and Configure InfluxDB 2 on Debian 12

Introduction This guide explains how to Install and Configure InfluxDB 2 on Debian 12 on Debian 12 Bookworm. Debian Bookworm uses systemd for service management, nftables as the underlying packet filter (with ufw or iptables front-ends still available), and AppArmor for mandatory access control. Every command is designed for a minimal Debian 12 install with […]

Read more
How to Secure PostgreSQL on Oracle Linux 9 — step-by-step Oracle Linux 9 tutorial on Progressive Robot

How to Secure PostgreSQL on Oracle Linux 9

Introduction Setting up secure postgresql on oracle linux 9 on a Oracle Linux 9 server is a common task for system administrators, DevOps engineers, and site reliability engineers. This guide explains how to Secure PostgreSQL on Oracle Linux 9, with all the commands you need, the SELinux and firewalld considerations to keep in mind, and […]

Read more
How to Configure NetworkManager on Debian 12 — step-by-step Debian 12 tutorial on Progressive Robot

How to Configure NetworkManager on Debian 12

Introduction Deploying configure networkmanager on debian 12 on a Debian 12 Bookworm machine is straightforward thanks to Debian’s policy-compliant packaging. Unlike rpm-based distributions, Debian stores configuration helpers in /etc/default/, uses update-rc.d for older init scripts, and provides dpkg-reconfigure for interactive package configuration. This tutorial stays on the systemd path throughout. Prerequisites You will need a […]

Read more
Common Problems 120025

Debian 12 SSH Public Key Authentication Denied

🟠 High   ⏱ 5–30 min  Last verified: 2 September 2023 Affected versions: Debian 12 📖 ~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 & […]

Read more
Common Problems 117060

Ubuntu 22.04 LTS Multipath Device Names Change After Reboot

🟡 Medium   ⏱ 5–30 min  Last verified: 2 September 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 […]

Read more
Common Problems 112465

Windows Server 2019 — PowerShellGet install-module fails with repository policy is untrusted — Fix & Prevention

🟡 Medium   ⏱ 5–30 min  Last verified: 2 September 2023 Affected versions: Windows Server 2019 📖 ~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 […]

Read more
How to Profile Application Performance with perf on RHEL 9 — step-by-step RHEL 9 tutorial on Progressive Robot

How to Profile Application Performance with perf on RHEL 9

The perf tool is the Linux kernel’s built-in performance analysis framework, capable of sampling CPU events, tracing system calls, counting hardware performance counters, and generating flame graphs — all without any changes to the application under test. On RHEL 9, perf integrates tightly with the kernel’s BPF and tracepoint subsystems, making it one of the […]

Read more
How to Configure OpenDKIM with Postfix on Debian 12 — step-by-step Debian 12 tutorial on Progressive Robot

How to Configure OpenDKIM with Postfix on Debian 12

Introduction This guide explains how to Configure OpenDKIM with Postfix on Debian 12 on Debian 12 Bookworm. Debian Bookworm uses systemd for service management, nftables as the underlying packet filter (with ufw or iptables front-ends still available), and AppArmor for mandatory access control. Every command is designed for a minimal Debian 12 install with the […]

Read more
Common Problems 120064

Debian 12 SSH Public Key Authentication Fails

🟠 High   ⏱ 5–30 min  Last verified: 1 September 2023 Affected versions: Debian 12 📖 ~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 & […]

Read more
CHAT