Linux server guides

Short, plain guides to running your own server. Each one is written for people who are new to it.

• What is a VPS?A VPS is your own slice of a bigger server, with its own system, address and access. Here is how it differs from shared hosting and how to pick a size.
• How to connect to a Linux server over SSHConnect to your Linux server with SSH in three steps: get the key, set its permissions and run one command. Includes fixes for common errors.
• How to open a port on a Linux serverOpen a port for your app, limit it to your own address and close it again. A short guide to ports and firewalls on a cloud server.
• Why you should snapshot a server before changing itA snapshot saves the whole disk so you can go back if an update goes wrong. How to take one, restore it and switch on nightly backups.
• How to install Docker on UbuntuInstall Docker and Compose on an Ubuntu server in one click from the ZaRHost panel, or by hand with the official script. Includes a quick test.
• Ubuntu, Debian, AlmaLinux or Rocky Linux: which should you choose?How to pick a Linux system for your server. A plain comparison of Ubuntu, Debian, AlmaLinux and Rocky Linux, and which suits what you want to run.