A: This is a deliberate design choice based on Performance and Transparency.
1. The “No Black Box” Philosophy Tools with block-level deduplication chop your files into millions of tiny data chunks and store them in proprietary database/container formats. To read your data, you must use their specific software. If that tool breaks or becomes obsolete, your data is lost. BmuS takes a different approach: Your files are stored as normal, readable files on the disk. You can plug your backup drive into any computer and open your photos or documents without needing BmuS installed. We prioritize recoverability over maximum storage efficiency.
2. Technical Limitations of Bash Block-level deduplication requires calculating complex hashes (checksums) for millions of data blocks in real-time. Compiled languages like C, Go, or Python can do this efficiently. BmuS is written in Bash (shell script). Attempting to implement block-level logic in Bash would make the backup extremely slow and consume massive amounts of CPU/RAM, which goes against our goal of running smoothly on low-power devices like Raspberry Pis.
3. The Trade-off
- Block-Level (Others): Saves more space (especially for VMs), but locks your data into a specific format.
- File-Level (BmuS): Saves slightly less space, but your data remains in standard, human-readable formats (Zero Vendor Lock-in).