Linux Server Basics: 15 Commands Every Website Owner Needs

If you run a website on a small cloud server, a handful of commands cover almost everything. Connect with SSH, then:

Health

df -h                 # disk space per drive; act when Use% passes ~85%
free -m               # memory in MB; "available" is what matters
uptime                # load average; compare with the number of CPUs (nproc)
top                   # live view of busy processes (press q to quit)

Services

systemctl status nginx          # is the web server running?
sudo systemctl reload nginx     # apply config changes without dropping visitors
sudo nginx -t                   # test the config BEFORE reloading
sudo systemctl restart php8.3-fpm

Logs

sudo tail -n 50 /var/log/nginx/error.log      # last 50 errors
sudo tail -f /var/log/nginx/access.log        # watch visits live (Ctrl+C to stop)
journalctl -u nginx --since "1 hour ago"

Files

du -sh /var/www/*               # which site uses the most space
ls -lh                          # list files with sizes and permissions
sudo cp file.conf file.conf.bak # back up before editing anything
sudo nano file.conf             # simple editor: Ctrl+O save, Ctrl+X exit

Updates

sudo apt update && sudo apt upgrade     # install security updates

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