# Archive

[← Documentation index](../index.md) · [Guided first pass](../first-pass.md)

![Archive locations and plans](../images/archive.png)

**What it is for.** Moving a finished album out of active storage onto another disk,
while keeping everything the library knows about it.

**What you decide.** Which album, which destination, and whether to accept the
reclaimed space in exchange for needing that medium mounted to see the originals
again.

**What it changes.** Files are copied to the archive location, verified there, and
only then removed from the library. The asset keeps its id, its hashes, its
decisions, its analysis, its upload history, and a durable preview thumbnail;
`current_path` becomes null and availability becomes `archived_online` or
`archived_offline`.

**What it refuses.** Preflight blocks on: an unverified upload, a checksum that no
longer matches the uploaded bytes, an unmounted or unwritable destination,
insufficient free space plus the configured reserve, a destination that already
holds unexpected paths, a missing durable thumbnail, and any conflicting job. The
source is **never** removed before the archived copy is verified — not because Immich
reported success, which is an ingest, not a backup.

## Offline is not missing

An archived photo whose medium is unplugged is `archived_offline`. It still appears
in search, still participates in duplicate detection through its retained hashes and
thumbnail, and is never reported as lost. If a full-resolution comparison is needed,
the application asks you to mount the named medium rather than guessing.

## Restore

Restore is planned and journaled like everything else: the medium must be online, the
bytes are copied back and verified into a collision-free destination, a new active
path is registered, and a reconciliation scan follows. Existing safety, analysis,
EXIF, and upload state stay valid when hashes match — and when they do not, the
result is a visible `divergent` state rather than silent acceptance of a different
file.

Next: [diagnostics](diagnostics.md).