# Debian/Ubuntu
apt update && apt upgrade -y
apt install nginx
apt remove nginx
apt autoremove

# RHEL/CentOS
dnf update
dnf install nginx
dnf remove nginx

uname -a           # Kernel info
hostnamectl        # System info
lscpu              # CPU info
free -h            # Memory usage
df -h              # Disk usage
ip addr            # Network interfaces

journalctl -u nginx          # Service logs
journalctl -f                # Follow logs
tail -f /var/log/syslog      # System logs
dmesg                        # Kernel messages

ps aux | grep nginx
top / htop
kill -9 <pid>
pgrep nginx
pkill nginx