System Administration Commands

Last reviewed: July 11, 2026

This is a general command reference, not a version-pinned runbook. Check the installed version, current official documentation, and the target account, host, and path before use. Commands that deploy, destroy, delete, prune, sync, upgrade, or change system settings can cause cost, downtime, or data loss; preview changes and back up where appropriate.

uname -a
cat /etc/os-release
lscpu
free -h
df -h
lsblk
ip addr show
ip route show

Capture these basics first when documenting a server incident.

ls -la
find /path -name "*.log"
du -sh /path/*
tail -f /var/log/syslog
grep "error" /var/log/syslog
tar -czf archive.tar.gz folder/

Use tail -f for live logs and grep for narrowing down historical evidence.

sudo systemctl status nginx
sudo systemctl restart nginx
sudo journalctl -u nginx -f

ping -c 4 8.8.8.8
ss -tuln
lsof -i :80
curl -I https://example.com

Start with service state, then check listening ports and the external HTTP path.