Btrfs Deep Dive: The B‑Tree Filesystem Explained
Table of Contents Introduction Historical Context & Design Goals Core Architecture: The B‑Tree Model 3.1 Node Types and Layout 3.2 Copy‑on‑Write Semantics Key Features of Btrfs 4.1 Subvolumes & Snapshots 4.2 RAID Levels & Data Redundancy 4.3 Online Defragmentation & Balancing 4.4 Checksum & Self‑Healing 4.5 Quota Management & Project Quotas Practical Administration 5.1 Creating a Btrfs Filesystem 5.2 Managing Subvolumes 5.3 Taking & Restoring Snapshots 5.4 Balancing and Adding Devices 5.5 Monitoring Health & Repairing Performance Considerations 6.1 IO Patterns & Workloads 6.2 Tuning Parameters Real‑World Use Cases Limitations & Known Issues Future Roadmap Conclusion Resources Introduction Btrfs—pronounced “B‑tree file system” or “Better FS”—is the most modern copy‑on‑write (CoW) filesystem native to the Linux kernel. Since its first commit in 2007, Btrfs has evolved from an experimental prototype to a production‑ready storage solution that rivals traditional filesystems like ext4 and XFS while offering features traditionally found only in enterprise‑grade storage arrays. ...