Back Up and Restore a Hytale Server

Understand what to protect

The official manual documents this layout:

• universe/ contains worlds and player data; each world is under universe/worlds/ with its config.json;
• config.json configures the server;
• permissions.json, whitelist.json and bans.json control access;
• mods/ contains active .zip and .jar files;
• auth.enc and auth.key are authentication secrets requiring strict access;
• logs/ connects a backup to a build and incident.

A world-only copy may load with wrong permissions or plugins. Record Hytale build, Java version and mod checksums too.

Enable native backups

The server accepts:

--backup --backup-dir backups --backup-frequency 30

Frequency is in minutes and the official wrappers use 30. Put the directory on monitored storage, ideally replicated off-host. A local backup protects against a player error but not disk failure or compromise.

The updater has RunBackupBeforeUpdate: true, but the manual states that it requires a configured backup directory. Verify logs and a real archive before relying on it.

Create and verify a manual restore point

Restore without overwriting the last healthy copy

1. Stop the server and archive the failed state, including logs.
2. Install Hytale and Java versions compatible with the backup. Restore the same mod list before opening the world.
3. Move current universe/ aside rather than deleting it. Put back the complete saved universe and matching JSON files.
4. Restore auth secrets only when required and through a secure channel. Re-authentication may be safer after suspected leakage.
5. Start in restricted mode. Check worlds, UUIDs, players, inventories, permissions, whitelist, mods and ability to create a new backup.
6. Stop and start again before reopening.

A practical retention policy

Keep several generations: frequent recent backups, daily points and archives before every update or mod change. Monitor disk space and test restores instead of keeping unlimited unverified files. The Hytale update guide explains staging; the mod guide covers compatibility.

Frequently asked questions