If you manage Linux servers long enough, you eventually hit this moment: Server is slow… users are shouting… and logs are everywhere. /var/log/messages /var/log/secure /var/log/nginx/access.log /var/log/nginx/error.log /var/log/mysql/error.log /var/log/audit/audit.log /app/logs/*.log /docker/containers/*/*.log So what do you do? You SSH into the box and start the ancient ritual: [root@siddhesh ~]# tail -f /var/log/messages [root@siddhesh ~]# tail -f /var/log/nginx/error.log

Introduction When migrating applications to the cloud, databases are often the most critical and sensitive components. A poorly planned database migration can lead to downtime, data loss, or performance issues. In this hands-on guide, we will migrate a MySQL database from a Linux server to Amazon Aurora (MySQL-Compatible)  using AWS RDS. This walkthrough is ideal for DevOps engineers, cloud engineers, and anyone learning AWS database migration. What You’ll Learn How to create

Introduction In modern cloud environments, auto scaling  is critical for high availability, performance, and cost optimization. Instead of running multiple servers all the time, AWS allows you to automatically scale EC2 instances based on load . In this blog, we will configure: Apache Web Server on EC2 Auto Scaling Group (ASG) Launch Template Target Tracking Policy Scale out when CPU > 5% Automatically launch a second Apache instance This setup is ideal for: Web applications

📌 Overview Prometheus Node Exporter provides excellent system-level metrics, but in real-world production environments, we often need custom application metrics  — for example: Postfix mail queue size Service status running/failure Application health Queue depth In this blog, we will implement a custom Node Exporter metric  to monitor postfix mail queue and visualise it in Grafana , using the textfile collector,  the recommended and production-safe approach. 🧠 Architecture

Introduction A Linux shutdown is more than just turning off a machine — it is a controlled process that protects running services, active users, and critical data. Understanding what happens during shutdown helps administrators troubleshoot delays, prevent corruption, and manage systems more confidently. [root@siddhesh ~]# shutdown -h now But very few actually know what happens after this command is executed . A shutdown is not just turning off the power.It is a well-orches

Disclaimer : This blog is strictly for educational and authorized security testing  only. Always take written permission before testing any application. Unauthorized testing is illegal. Introduction SQL Injection is still one of the most common and dangerous web vulnerabilities. Even today, many internal tools, admin panels, and legacy applications are exposed due to weak input validation. sqlmap  is an open-source penetration testing tool that automates the process of detect

System integrity is one of the most overlooked areas in Linux security. Firewalls, SELinux, and antivirus tools are common, but they do not tell you if critical system files were modified silently . This is where AIDE (Advanced Intrusion Detection Environment)  fits perfectly. In this blog, I’ll walk through what AIDE is, how it works, how to configure it properly , and how to interpret its output  on RHEL, Rocky Linux, and CentOS . All commands shown below were executed manu

Managing the ARP cache effectively is essential for maintaining smooth network communication on Linux systems. Both Red Hat Enterprise Linux (RHEL) and Rocky Linux rely on the Address Resolution Protocol (ARP) to map IP addresses to MAC addresses within a local network. Understanding how to view, modify, and clear the ARP cache can help troubleshoot network issues, improve security, and optimize system performance. This post explores ARP cache management on RHEL and Rocky Lin

awk is a powerful text-processing tool available in Linux and UNIX. It is primarily used for pattern scanning, text manipulation, and...

Introduction of Auditd Keeping track of what happens on your Linux system is crucial, especially for security and compliance. Linux...

If you’ve ever needed to troubleshoot network connections on a Linux system, you’ve likely encountered tools like netstat . But there’s a...

Monitoring file system activity in real-time is crucial for system administrators, developers, and DevOps engineers. Whether you’re...

Postfix is a popular mail transfer agent (MTA) used to route and deliver email on Linux servers. Sometimes, it’s necessary to run...

Logging is a critical aspect of system administration, helping you keep track of events, diagnose issues, and maintain security. While...

When managing a web server, it's essential to protect your site from unwanted traffic and malicious activity. Nginx, a popular web...

When running a web server, security and privacy are key considerations. By default, Nginx reveals its server name in the HTTP headers,...

In this blog, I'll guide you through installing Nginx from source on a Linux system. We'll walk through each step, from installing the...

Debugging is an essential part of maintaining and optimizing your NGINX server. It provides detailed logs that can help you troubleshoot...

Introduction to MySQL Triggers In the realm of database management, automation is key to maintaining data integrity and enforcing...

Load balancing can be generally divided into two main types: static and dynamic , each with different methods and applications. Static...