System Administration Guide

Comprehensive reference for modern system administrators

Core Responsibilities

User Management

Create, modify, and delete user accounts with proper permissions

sudo useradd -m -s /bin/bash username

Service Management

Control system services using init systems

systemctl restart nginx

Package Management

Handle software installation and updates

apt update && apt upgrade -y

Security Practices

Firewall Configuration

Implement UFW or firewalld for network protection

ufw allow ssh

SSH Hardening

Use key-based auth and disable root login

PasswordAuthentication no

Regular Audits

Check for vulnerabilities with Lynis

Monitoring & Logging

Essential Tools

  • Prometheus
  • Grafana
  • ELK Stack
  • Nagios

Key Metrics

  • CPU Usage
  • Memory Utilization
  • Disk I/O
  • Network Throughput

Backup Strategies

Full Backups

Frequency: Weekly

tar -czvf backup.tar.gz /data

Incremental

Frequency: Daily

rsync -av --link-dest=/previous_backup /source /destination

Off-site

Frequency: Real-time

aws s3 sync /backup s3://bucket-name

Certification Path

Entry

  • CompTIA Linux+
  • LPIC-1

Intermediate

  • RHCSA
  • LFCS

Advanced

  • RHCE
  • CKA

Additional Resources

Linux Documentation

https://www.kernel.org/doc/

Sysadmin Community

https://www.reddit.com/r/sysadmin