bcpierce00/unison
Unison
Unison is a bidirectional file synchronization tool that keeps two copies of a directory identical by automatically propagating changes in both directions. It operates over an encrypted SSH transport layer, allowing secure synchronization between different hosts and operating systems without a central server.
The tool uses a bidirectional reconciliation engine to compare replicas and compute a minimal set of actions for agreement, handling both automatic merging of non-conflicting changes and clear reporting of conflicts that require manual resolution. Unison optimizes transfers by sending only changed file blocks via delta compression, making it suitable for slow or bandwidth-limited network links. It also supports real-time filesystem watching, automatically detecting changes and propagating them without manual intervention.
Additional capabilities include fast modification-time checks that skip unmodified files before hashing, replica-based state archives that store local metadata and content hashes for efficient change detection, and built-in support for synchronizing across platforms.
Features
- Bidirectional Folder Synchronization - Synchronizes files between two directories or hosts in both directions, automatically merging non-conflicting changes.
- Delta Transfer Protocols - Transfers only changed file blocks using rolling checksums to minimize bandwidth usage.
- SSH Encryption - Communicates between hosts over an encrypted SSH channel using a custom protocol.
- Bidirectional File - Provides the core reconciliation engine that compares two replicas to compute synchronization actions.
- Sync Conflict Resolution - Detects conflicting changes between two copies of the same directory and provides mechanisms to resolve them.
- File Synchronization Conflicts - Detects conflicting updates between two file copies and presents them for manual resolution.
- Slow Link Optimizations - Efficiently syncs large files or directory trees over low-bandwidth connections using incremental updates.
- Real-time Synchronization - Watches the filesystem for changes and synchronizes them automatically without requiring manual actions.
- Delta Compression Bandwidth Optimizations - Transfers only changed file blocks using delta compression to minimize bandwidth usage on slow network links.
- File Watchers - Watches the filesystem for changes and synchronizes them automatically without requiring manual actions.
- Cross-Platform Sync Configurations - Synchronizes files between different operating systems and network locations reliably.
- Replica Metadata Archives - Stores local file metadata and content hashes on each host for efficient change detection.
- Timestamp-Based Change Checks - Implements fast modification-time checks that skip unmodified files before hashing.
- Filesystem Change Monitors - Watches the filesystem for updates and propagates changes in real time without manual intervention.
- File Management - Listed in the “File Management” section of the Awesome Selfhosted awesome list.
- File Storage and Sync - File synchronization tool for cross-platform environments.
- File Synchronization - File synchronization tool for cross-platform environments.
- Audio and Subtitle Tools - File synchronization tool for keeping media assets updated.
Star history
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