PRE-MIGRATION AUDIT / LIBRARYPROOF FIELD NOTE
How to audit an Apple Photos library before moving it
A Photos library can look healthy in the app while still depending on external references, cloud downloads or package structures that another Mac may not interpret the same way. A useful preflight separates what is observable from what is only assumed.
1. Keep an untouched source
Close editing workflows and keep a backup before any migration. An audit should read the selected package or export without repairing it, changing its database or forcing cloud downloads. The point is to preserve evidence before movement.
2. Inventory readable local bytes
Count and hash regular media files that are actually readable on the Mac. These files can support a local export-size estimate. A database row without readable bytes cannot be included in that estimate.
3. Review explicit references
When a safely interpreted record or symbolic link exposes an external path, check whether a regular file is present and readable there. Keep absent references separate from cloud-associated records; they are different migration risks.
4. Preserve unknown evidence
If the Photos database schema is unsupported or a record cannot be matched safely, leave it unknown. Do not turn uncertainty into a green check or a confirmed missing-original count.
5. Export a portable receipt
Keep machine-readable JSON and CSV, a human-readable checklist and SHA-256 hashes together. Reverify the source before publishing the evidence package so a stale audit is not mistaken for current state.