Btrfs recovery
Btrfs combines copy-on-write metadata, checksums, subvolumes, snapshots and optional multi-device profiles. A simple mount error may represent an incomplete device set, damaged tree roots or hardware I/O failure.
Understand the symptom
The filesystem tracks extents, checksums, directories, subvolumes and device membership through copy-on-write trees. RAID-like profiles can distribute metadata and data differently across members. Missing or stale devices, interrupted balance, bad sectors or damaged roots can prevent mounting even when many extents remain readable.
What you may see
Tree blocks may be unreadable, stale or inconsistent with the expected generation.
The filesystem expects one or more members that are absent, stale or misidentified.
A particular root or path may be unavailable while other filesystem generations survive.
Underlying hardware can prevent Btrfs from reading valid mirrored or alternate copies.
Protect the source
Repair can make irreversible changes and is not a first recovery step.
An unstable device set can deteriorate during broad redistribution.
Stale and current members must be identified before configuration changes.
Do this now
Prevent containers, shares, databases and snapshots from writing to the filesystem.
Keep removed, failed, replacement and cache devices labeled with original positions.
Record kernel messages, filesystem show output, UUIDs and commands already attempted.
Protect failing devices before attempting tree or device-set reconstruction.
NEPFOSYS process
NEPFOSYS identifies filesystem UUIDs, profiles, generations and the complete member set.
Readable devices are imaged individually with errors and missing regions documented.
Surviving roots, subvolumes, snapshots, extents and checksums are evaluated away from the originals.
A clear next step
Start a case with the exact symptoms, incident timeline, prior attempts, encryption details, and the files that matter most. NEPFOSYS will route the case to the appropriate DFW intake or nationwide mail-in path.
Start with a case reviewQuestions, answered
Not on the only copy. It changes metadata and should be considered only after images and a clear recovery plan exist.
It depends on the data and metadata profiles, which extents were stored on that member and the health of remaining devices.
No. Snapshots share underlying extents and metadata; device or tree damage can affect multiple snapshots.
DFW local · Nationwide mail-in