authentication

Common Problems 115946

Ubuntu 26.04 LTS – SSH login fails due to incorrect permissions on ~/.ssh – Fix & Prevention

🟠 High   ā± 5–30 min  Last verified: 3 July 2026 Affected versions: Ubuntu 26.04 LTS šŸ“– ~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 116014

Ubuntu 26.04 LTS – clock drift causes TLS and authentication failures – Fix & Prevention

🟠 High   ā± 5–30 min  Last verified: 3 July 2026 Affected versions: Ubuntu 26.04 LTS šŸ“– ~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 MySQL Master-Replica Replication on RHEL 10 — step-by-step RHEL 10 tutorial on Progressive Robot

How to Set Up MySQL Master-Replica Replication on RHEL 10

Introduction RHEL 10 ships with a stable, security-hardened base that makes deploying set up mysql master-replica replication both straightforward and auditable. This tutorial covers the complete procedure for how to Set Up MySQL Master-Replica Replication on RHEL 10, including dnf module streams where applicable, systemd unit management, and the firewalld rules required for network-facing services. […]

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How to Set Resource Limits with /etc/security/limits.conf on RHEL 10 — step-by-step RHEL 10 tutorial on Progressive Robot

How to Set Resource Limits with /etc/security/limits.conf on RHEL 10

Introduction This tutorial demonstrates how to Set Resource Limits with /etc/security/limits.conf on RHEL 10 on RHEL 10. 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 RHEL 10 system with the default AppStream […]

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How to Set Up Software RAID with mdadm on Ubuntu 26.04 — step-by-step Linux tutorial on Progressive Robot

How to Configure Samba File Sharing on Ubuntu 26.04

Samba implements the SMB/CIFS protocol on Linux, enabling file and printer sharing with Windows, macOS, and other Linux machines. It is the standard way to create Linux-based file servers accessible to Windows clients. This guide configures Samba on Ubuntu 26.04 LTS. Tested and valid on: Ubuntu 26.04 LTS Prerequisites Ubuntu 26.04 LTS A user with […]

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Common Problems 116038

SSH login fails after hardened AppArmor profile update

🟠 High   ā± 5–30 min  Last verified: 30 June 2026 Affected versions: Ubuntu 26.04 LTS šŸ“– ~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 Apache mod_security WAF on RHEL 10 — step-by-step RHEL 10 tutorial on Progressive Robot

How to Configure Apache mod_security WAF on RHEL 10

Introduction Setting up configure apache mod_security waf on a RHEL 10 server is a common task for system administrators, DevOps engineers, and site reliability engineers. This guide explains how to Configure Apache mod_security WAF on RHEL 10, with all the commands you need, the SELinux and firewalld considerations to keep in mind, and how to […]

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How to Set Up Software RAID with mdadm on Ubuntu 26.04 — step-by-step Linux tutorial on Progressive Robot

How to Install Netdata on Ubuntu 26.04

Netdata is an open-source, real-time performance monitoring tool that provides per-second metrics for CPUs, RAM, disks, network, processes, and hundreds of applications out of the box. It requires zero configuration to get started. This guide installs Netdata on Ubuntu 26.04 LTS. Tested and valid on: Ubuntu 26.04 LTS Prerequisites Ubuntu 26.04 LTS A user with […]

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How to Set Up a Git Server with Gitea on Ubuntu 26.04 — step-by-step Linux tutorial on Progressive Robot

How to Set Up a Git Server with Gitea on Ubuntu 26.04

Gitea is a lightweight, self-hosted Git service written in Go. It provides a GitHub-like interface with repositories, issues, pull requests, and actions CI/CD, but runs on minimal hardware. This guide installs Gitea on Ubuntu 26.04 LTS with Nginx and a PostgreSQL database. Tested and valid on: Ubuntu 26.04 LTS Prerequisites Ubuntu 26.04 LTS with Nginx […]

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How to Install Ansible on Oracle Linux 10 — step-by-step Oracle Linux 10 tutorial on Progressive Robot

How to Install Ansible on Oracle Linux 10

Introduction This tutorial demonstrates how to Install Ansible on Oracle Linux 10 on Oracle Linux 10. 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 10 system with the default AppStream […]

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