Linux & System Administration

A comprehensive practical guide to Linux package management covering APT, DNF, and YUM. Learn installation, upgrades, repository management, security, automation, and troubleshooting across Debian/Ubuntu and RHEL/CentOS/Fedora systems with real commands and examples.

Monitor Linux system performance with htop for real-time process viewing, iostat for disk I/O analysis, and sar for historical data. htop shows CPU/memory usage and process management. iostat reveals storage bottlenecks and device utilization. sar tracks long-term trends for capacity planning.

Master Linux firewall configuration with UFW and iptables. Learn safety practices, default policies, SSH hardening, rate limiting, NAT setup, and troubleshooting. Complete guide for sysadmins covering basic UFW commands to advanced iptables rules with examples.

Complete guide for setting up Apache, Nginx, or Lighttpd web servers on Linux. Covers installation, virtual hosts, HTTPS with Let's Encrypt, firewall configuration, SELinux setup, performance tuning, and monitoring. Includes commands for Debian/Ubuntu and RHEL/CentOS systems.

A comprehensive guide to 25 essential Linux commands every system administrator must master. Covers file management, process control, system monitoring, networking, and security tools like ls, grep, systemctl, ssh, and rsync with practical examples and safety tips.

Linux disk management guide covering fdisk partitioning, LVM setup with physical volumes, volume groups and logical volumes, plus mount points and filesystem creation. Includes step-by-step commands for safe disk operations, resizing, and persistent mounts via fstab.

Master Linux cron jobs and task scheduling with this comprehensive guide covering crontab syntax, environment setup, security best practices, troubleshooting, and systemd timers. Learn to automate backups, maintenance tasks, and system operations reliably across Linux environments.

A comprehensive technical comparison of systemd and SysVinit for Linux administrators. Covers architecture differences, performance benchmarks, security considerations, and practical recommendations for servers, embedded systems, and containers.

Secure SSH access on Linux servers by using key-based authentication, disabling password login, restricting root access, hardening sshd config, implementing firewall rules, enabling fail2ban, monitoring logs, and using 2FA where possible.

Linux system administrators covering networking fundamentals, interface configuration, routing, VLANs, firewalls, VPNs, performance tuning and troubleshooting with hands-on examples for Ubuntu RHEL CentOS.

The Linux filesystem hierarchy is an organized tree structure starting from root (/). Key directories include /bin for essential commands, /etc for configuration files, /var for variable data like logs, /home for user files, and /usr for installed software.

Complete guide to Linux user and group management covering useradd, usermod, groupadd commands, sudo configuration, password policies, file permissions, and security best practices. Includes step-by-step workflows for creating, modifying, and deleting accounts with real examples.