Chronos Backups

^{The wonderful mod icon and banner were created by Mylèna Yarah Krijnen.} Chronos Backups is a multi-loader, multi-version Minecraft backup utility. Saves only the most important parts of your world, keeping backups smaller.

Features

• Multi-version, multi-loader architecture (Fabric, NeoForge, Forge, Bukkit, Spigot, Paper, Purpur and Folia).
• Scheduled and manual backups via an in-game /chronos command with a configurable permission level.
• Backups are pruned and filtered to only include the most important parts of your world, keeping backups much smaller than traditional backups.
• Configurable file copy blacklist to exclude specific files and folders from the backup, prefilled with common server-related files and folders.
• Cloud sync: Upload completed backups to your preferred cloud storage provider, with the option to automatically delete local copies after a successful upload. Currently supported:

Commands

Performance and benchmarks

On default settings, Chronos backups typically shrink to about 1–15% of the original world size. When Distant Horizons and/or Voxy data is filtered out as well, the backup is often under 7% of the full on-disk footprint (world + LOD).

Cloud sync

Chronos can upload finished backups to a remote cloud provider, then optionally remove the local copy.

Behaviour

• Local backups missing from the remote are uploaded, including catch-up after a failed upload or a restart.
• maxStoredBackups also caps how many Chronos backups each enabled provider keeps per world (oldest removed first). Values below 1 disable automatic removal locally and remotely.
• If shouldKeepLocalBackups is false, a backup is deleted from disk (only after it has been uploaded successfully). When multiple worlds would map to the same remote folder (e.g. two servers both named "world"), Chronos attempts to resolve this by assigning a unique alias in chronos-alias.txt instead of overwriting. This favors safety over storage, so orphaned remote data may remain. Watch the console when enabling cloud sync on multiple servers.

Providers

Currently supported: . Enable it with googleDriveEnabled = true, restart, then follow the authorization URL printed in the console. Sign in once, tokens are stored on that machine under google-drive-tokens/. (Anyone with access to this token will be able to upload and delete backups from your Google Drive. They will not be able to access any other files in your Google Drive.) Google Drive was chosen because it is the most popular cloud provider, and has the most generous free tier, with 15GB of storage. OneDrive and Dropbox are planned. They are not available yet.

Limitations

Chronos prioritizes aged world data, chunks that do not yet count as "old enough" can be left out of a backup. If you enter a new chunk, change blocks or items, and a backup runs before that area is included, those changes may be missing from that backup (depending on configuration). That situation is seen as extremely rare and can only cause loss on restore, never duplication.

Supported versions

All currently supported versions are listed below.

Configuration

The mod's configuration is stored in the config/chronos.toml file. This file is automatically created when the mod is first run, and is located in the config folder. For the forseeable future, there is no GUI configuration available. Config options include:

• backupFolderName: The name of the folder that will contain the backups.
• pruneChunks: Whether chunk pruning is enabled for backups.
• pruneTimeRequirementSeconds: Minimum playtime (in seconds) for a chunk to count toward world pruning.
• pruneMaxWorkerThreads: Maximum worker threads for pruning. 0 (or less) means "auto" (pruner picks a sensible default).
• scheduleBackups: Whether to run backups on a timer.
• backupIntervalSeconds: Seconds between automatic backup runs.
• maxStoredBackups: Maximum backups kept per world locally and on each enabled cloud destination. After a successful backup, oldest local backups are removed if the limit is exceeded. Cloud sync also trims remote Chronos backups to this cap. Recommended value: 5. Values lower than 3 can be used to save space, but risks serious data loss if a catastrophic error occurs. Values below 1 disable automatic removal.
• compressionMethod: Whether to compress the backups into a zip file or store it as an uncompressed folder. Accepts "zip" or "none".
• googleDriveEnabled: Enable Google Drive as a cloud sync destination (see Cloud sync).
• shouldKeepLocalBackups: When true, keep local backups after a successful cloud upload. When false, delete each local backup once it has been uploaded.
• commandRequiredPermissionLevel: Permission level required to run /chronos.
• copyBlacklist: Folders and files to exclude from the backup. This list may be out of date. To see the latest available configuration options and their descriptions, see ChronosTomlSpec.java.

Nightly releases

Github Actions automatically builds and uploads nightly releases to the GitHub Releases page. These are not the same as stable releases found on Modrinth, CurseForge or Github Releases, and should not be relied upon or assumed to be stable.