linux - ITNotes

Networking tutorial - IT technology blog

Nmap Network Scanning: How to Detect Open Ports and Vulnerabilities Fast

March 7, 2026

Learn how to use Nmap for fast network scanning and vulnerability detection through real-world incident response scenarios. Covers port scanning, service version detection, NSE vulnerability scripts, and a practical scan sequence for sysadmins and security engineers.

DevOps

Docker for Beginners: From Install to Running Your First Container

March 7, 2026

Docker solves the classic "works on my machine" problem by packaging your app and its entire environment into a portable container. This guide walks you through installing Docker, understanding core concepts, building your first custom image, and practical tips for real-world usage.

HomeLab

Build a Home Lab with Proxmox VE: A Practical Guide for Beginners

March 6, 2026

Learn how to set up a home lab using Proxmox VE — a free, open-source bare-metal hypervisor. This guide walks you through installation, VM creation, and LXC containers so you can practice real IT skills on cheap hardware without cloud costs.

Linux

LVM on Linux: Flexible Disk Management Without the Headaches

March 6, 2026

LVM (Logical Volume Manager) lets you resize Linux partitions live, add disks to an existing storage pool, and take point-in-time snapshots — all without downtime. This guide covers PV/VG/LV concepts and the practical commands that matter most in real-world server management.

Linux

How to Troubleshoot ‘Disk Full’ Error and Manage Disk Space on Linux

March 6, 2026

Linux disk full errors can crash your applications instantly. This guide walks through practical commands to diagnose disk usage, recover space fast from logs, Docker, and caches, and set up monitoring to catch problems before they escalate.

Networking

IPv4 Subnetting Tutorial: How to Calculate Subnets Without Losing Your Mind

March 6, 2026

IPv4 subnetting is the skill that separates networking theory from practical network engineering. This tutorial walks through subnet calculations, CIDR notation, VLSM, and real-world allocation strategies with Python and Linux command examples.

DevOps

Ansible Server Configuration Automation: 6 Months of Production Reality

March 6, 2026

After six months running Ansible in production across multiple Ubuntu servers, here's an honest comparison against Puppet, Chef, and manual scripts — including real pros and cons, recommended project structure, and a working playbook to get started immediately.

Linux

Linux chmod and chown: What 3 Years of Managing 10+ VPS Taught Me About Permissions

March 6, 2026

After managing 10+ Linux VPS instances over 3 years, I've seen sysadmins take two very different approaches to chmod and chown — and only one holds up under pressure. Here's the full breakdown: what works, what backfires, and the exact permission model I apply to every new server.

Linux

How to Configure Nginx as Web Server and Reverse Proxy on Ubuntu

March 6, 2026

Running an app directly on port 3000 works right up until you need HTTPS, multiple backends, or proper static file serving. This guide walks through configuring Nginx as both a static web server and reverse proxy on Ubuntu, covering server blocks, proxy headers, SSL with Let's Encrypt, and the monitoring commands you'll reach for after every deploy.

DevOps

Prometheus + Grafana System Monitoring: A 6-Month Production Review

March 6, 2026

After six months running Prometheus and Grafana in production, here's an honest review of the stack — what works, where it struggles, and a complete setup guide to get you from zero to monitoring in under an hour.