First steps with a new server

Servers on the internet are scanned within minutes of going online. Do these first:

1. Change the password you received: run passwd.
2. Update the system:

apt update && apt upgrade -y      # Ubuntu / Debian
dnf upgrade -y                    # AlmaLinux / Rocky

3. Use SSH keys and turn off password login once your key works. See Connecting with SSH.
4. Turn on a firewall and allow only the ports you need (22, 80, 443): in IDX Panel's Firewall tab, or on the server with UFW.
5. Install the INSIDX agent to see memory and disk use and get alerts. See The INSIDX agent.
6. Set up backups before you put anything important on the server. See Backups and snapshots.