How to Back Up and Restore a Hytale Server World

To back up a Hytale server world, start the server with --backup --backup-dir backups --backup-frequency 30 so it saves a copy of the universe folder every 30 minutes, and run /backup before anything risky. To restore, stop the server, move the current universe folder aside, put the backed up copy in its place, and start the server. Your settings files (config.json, permissions.json, whitelist.json and bans.json) are separate from the world, so copy them too before big updates.

What to back up

A Hytale server keeps its world and its settings in different places:

The built in backup covers the universe, which is what you lose in a crash, a grief or a bad world update. The settings files are small and rarely change, but a fresh copy before each update costs nothing.

Step 1: Turn on automatic backups

The server takes backups itself when started with the backup options:

java -Xms4G -Xmx4G -XX:AOTCache=HytaleServer.aot -jar HytaleServer.jar --assets ../Assets.zip --backup --backup-dir backups --backup-frequency 30

The official start.sh and start.bat wrapper scripts already use these defaults. If you start the jar yourself, add them to your command.

How often to back up: every 30 minutes suits most servers. A busy server with lots of building might go to 15. Backups cost disk space, so check the folder now and then and clear out old ones you do not need.

Step 2: Take a backup on demand

Before an update, a big event or a risky plugin, take one by hand from the console:

/backup

This only works when the server was started with --backup-dir, because it needs to know where to write. If it does nothing, check your start command.

It is also worth running /world save --all first, so every loaded world writes its current state to disk before the copy is taken. The Hytale commands guide lists the other world commands.

Step 3: Keep a copy off the server

Backups on the same disk as the server do not help if the disk fails or the machine is lost. Every week or so, and always before a major update like Chapter 1:

1. Stop the server, or at least run /world save --all.
2. Copy universe, config.json, permissions.json, whitelist.json, bans.json and mods to another machine or cloud storage.

The general game server backup guide covers ways to automate off site copies.

How to restore a backup

1. Stop the server. Never swap world files while it runs.
2. Keep the current state. Rename universe to something like universe-broken. If the restore picks the wrong time, you can go back.
3. Find the right backup. Open the backup folder and pick the newest backup from before the problem, by its date and time.
4. Put it in place. Copy the backed up universe into the server folder as universe. If the backup is an archive, extract it first and check the result is a single universe folder with your worlds inside, not a folder nested inside another.
5. Restore settings if needed. If the problem involved operators, bans or the whitelist, copy those files back from your own copy too.
6. Start the server and join to check the world.

Restoring after a bad update

If an update breaks the world, restoring the universe alone may not be enough, because the new server version keeps running the same code. The wrapper scripts keep the previous server files in updater/backup/ after an update. Roll the server files back as described in updating a Hytale server, then restore a universe backup from before the update. An older server version may not load a world saved by a newer one, so pair the two from the same time.

Restoring one world on a multi world server

A server can run several worlds (/world list shows them). Each world has its own folder inside universe. To roll back only one, stop the server and replace only that world's folder from the backup, leaving the others as they are. Player data that travels between worlds can end up out of step, so tell players which world was rolled back.

Common problems

• /backup does nothing. The server was not started with --backup-dir.
• The restored world is empty. The folder ended up nested, like universe/universe/.... Move the contents up one level.
• Players lost items after a restore. Expected. Everything after the backup time is gone for everyone.
• The disk fills up. Old backups pile up. Delete the oldest, and keep the important ones off the server.

Hytale hosting with backups built in

We are preparing GamezServers Hytale servers with automatic world backups you switch on in settings, a backup interval you choose, one click backups from the panel, and a file manager for restores. They are not open yet. Join the waitlist on the Hytale server hosting page and we will email you as soon as you can deploy. The Hytale quick start shows what the plans will include.

FAQ

Does a Hytale server back up automatically?

Only when started with --backup and a backup folder. The official wrapper scripts turn it on with a 30 minute interval.

Where are Hytale server backups stored?

In the folder you pass to --backup-dir, usually backups inside the server folder.

What do I need to back up on a Hytale server?

The universe folder for the worlds and players, plus config.json, permissions.json, whitelist.json, bans.json and your mods folder.

Can I restore a backup while the server is running?

No. Stop the server first, or it may overwrite the restored files when it next saves.