# The Copy Map: What 14.7 Million Fingerprints Revealed

- Link: https://jcody.com/ai-projects/copy-map/
- Published: 2026-11-10T10:34:01-05:00
- Author: Jeffrey Cody

[AI Projects](https://jcody.com/ai-projects/) › The copy map

**Once every file had a sha256, the archive could answer a basic question:** how
many copies of this do I really have? The answer was lopsided.

## The map

Each bar pair shows distinct content (colored) against the total bytes stored for
it (grey), in TiB. Source: fingerprint report, Nov 7.

1 copy only

12.87 distinct, 12.87 stored

2 copies

11.43 distinct, 22.86 stored

3 copies

7.06 distinct, 21.19 stored

4 copies

6.00 distinct, 24.02 stored

5 copies

1.73 distinct, 8.65 stored

6 or more

4.43 distinct, 36.50 stored

■ exists once, protect first   ■ distinct content   ■ total stored. Full width is
40 TiB.

## What the map means

 * The 777,579 contents stored six or more times took **36.5 TiB** for 4.4 TiB of
   unique material. That is the long tail of twenty drive generations copying forward.
 * Meanwhile **771,861 contents existed exactly once**, each one a single disk failure
   from gone.
 * Theoretical reclaim across the fleet was **82.6 TiB**, before keeping any safety
   copy.
 * Of 126 TiB stored, about 43.5 TiB was distinct.

That one chart turns “my storage is a mess” into a ranked work order with a dollar
figure attached: protect the red bar first, reclaim from the tall grey bars last,
and only with proof.

## How the work order falls out

 1. **Protect:** copy the single-copy content to a second home, verified by hash.
 2. **Choose golden records:** by health and completeness first. Recency is only a 
    tiebreaker, because the newest copy was once the corrupted one.
 3. **Reclaim:** only where a content hash survives on at least two other disks, with
    written approval for each batch.
 4. **Compress:** only after hashes exist, with quality gates and parent-to-child links.

## Try it on your own data

You do not need 126 TiB for this to pay off. A marketing library, an engineering
share or twenty years of project folders all have the same shape. The first step
is a read-only walk of names, sizes and dates. In my measurements, 12,871 files 
and 2.88 TiB were walked in two seconds.

[Read the client playbook](https://jcody.com/ai-projects/client-playbook/)

[Tell me what you are sitting on](https://jcody.com/contact/?need=ai-projects)

_Figures from the Nov 7 fingerprint report. Percentages in the chart are to scale
against a 40 TiB full width._

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