This repository has been archived on 2026-09-03. You can view files and clone it, but you cannot make any changes to it's state, such as pushing and creating new issues, pull requests or comments.
The 7.x branch system stored Virtual Filesystem content as blobs in its
copy-on-write area (`_cow/`). 8.0 removed that system and stores content blobs
in the content-addressed store (`_cas/`), but the one-time layout migration only
moves entities — it never adopted the `_cow/` content blobs. A store that used
the VFS was left with every VFS-backed read throwing "Blob metadata not found"
and its pages 500ing, with no first-party recovery and the pre-upgrade backup
already removed on entity-migration "success".
Add an on-open recovery pass (`autoAdoptLegacyVfsBlobsIfNeeded`) that runs right
after the layout migration and adopts every orphaned `_cow/` blob into `_cas/` —
copying both the bytes and the metadata via the raw object primitives,
idempotently and non-destructively (the `_cow/` originals are never deleted). It
is a separate phase, not folded into the migration, so it also heals a store
already upgraded by an earlier 8.0.x that stranded the blobs (whose layout-
migration marker is stamped): it is gated on the presence of `_cow/` and its own
`_system/vfs-blob-adoption.json` marker. Filesystem-only; native-8.0 and non-VFS
stores no-op on a cheap existence check.
- `BaseStorage.adoptLegacyCowBlobs()` — the scan/copy primitive, returning
`{ cowBlobs, adopted, alreadyPresent, incomplete }`; skips (does not half-adopt)
a blob missing its bytes or metadata.
- `brain.vfs.adoptOrphanedBlobs()` — the explicit force path; self-initializes.
- Backup retention: the automatic pre-upgrade backup is now kept if any blob
can't be fully adopted (`incomplete > 0`), instead of being removed on
entity-migration success alone — a blob-parity gate the migration signal
cannot provide.
Adds an end-to-end integration test (storage-level adopt with idempotency and
incomplete handling; self-heal on reopen; the explicit API) and an upgrade guide.
David Snelling
c0f6ccd958