Requirements

What the machine, your network and your domain need before you run the installer.

Server

Operating system: Ubuntu Server 24.04 LTS, 64-bit Intel or AMD (x86-64). Start from a fresh installation.
Processor and memory: at least 4 cores and 8 GB, 16 GB if UniFi OS Server runs too. Plan more for Immich, Tdarr or many users streaming at once.
Disks: an SSD for the system, and a separate disk or NVMe for your media, mounted at /srv/data.
Access: a user with sudo rights and SSH.

Connect the server by cable. Wi-Fi works, but downloads, Plex and the VPN all suffer, and a UniFi controller must never depend on its own access point.
Give the server a fixed address in your router (DHCP reservation), for example 192.168.1.200. The docs call it <server-ip>, see Prepare the server.
With a domain, forward TCP 443 from your router to the server. For the VPN, also UDP 51820.
Access from outside needs a public IPv4 address of your own. Many cable and fibre lines, Starlink and LTE/5G routers share one address between customers (CGNAT, DS-Lite), and port forwarding has no effect there. The installer checks this, see Reachability, CGNAT & DynDNS.

Optional. Without a domain, CloudZH runs in LAN mode, only in your home network. See Domain or home network.

A domain whose DNS zone is managed by Cloudflare.
A Cloudflare API token with the permission Zone · DNS · Edit for this zone. Do not use the Global API Key.

Your license key (CZL-XXXXX-XXXXX-XXXXX-XXXXX) from your license email. A new server confirms itself by email, or uses CloudZH Setup from your customer account, which needs no confirmation.