Backup and restore

A backup worth keeping has two halves: what the game owns, and what the plugins own.

What to back up

Path	What	Changes when
worlds/	Every world, one directory per level-name	Continuously while players are online
keys/server_identity_key.pem	The server's identity key	Once
allowlist.json	The allow list	On allowlist edits
plugins/	Plugin packages, including plugins/hosihikari/	On install and update
config/hosihikari/	Server-side configuration overrides	On configuration edits
data/hosihikari/	Data the framework hands to plugins	While plugins run

The last three are the framework's. plugins/ is worth backing up even though it can be reinstalled: the exact package versions on a working server are part of what you are preserving.

Take one while the server is down

Stop the server, copy the paths above, start it again. This is the only method that cannot catch a half-written world.

Take one while the server is running

BDS can prepare a consistent copy of the world on demand. In the server console:

save hold
save query

save hold only asks the server to prepare; it returns immediately and the preparation runs in the background. Call save query repeatedly until it answers with a file list. Until then it reports that preparation is still in progress, and the files are not yet safe to copy.

The successful save query answer lists every file to copy and the length of each one. Copy exactly those files — not the whole worlds/ directory — and truncate each copied file to the length the server gave. The server keeps running during the copy, so a file can grow while you read it; the truncation is what makes the copy match the snapshot.

When the copy is finished, release the hold:

save resume

Then copy the framework paths normally. They are plain directories and are not covered by the world flush.

Restore

1. Stop the server.
2. Replace worlds/, keys/, and allowlist.json with the copies.
3. Replace plugins/, config/hosihikari/, and data/hosihikari/.
4. Start the server and check the log for the framework taking over and for the plugin list.

Restoring an older plugins/ alongside a newer framework is the usual cause of a plugin being refused on api_version. Restore the framework and plugins from the same date.

What a backup does not cover

• The BDS binary and its own files. Keep the server archive you installed from.
• The .NET runtime. Reinstall it rather than copying it.
• Anything a plugin writes outside data/hosihikari/. That path is the contract; a plugin that writes elsewhere is outside it, and you would need to know that plugin's layout.