System Administration

System Administration Commands

Linux / Unix system information, file operations, systemd, and network diagnostics.

System inspection
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.

Files and logs
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.

systemd and networking
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.