# USB08 compatibility-path HPT export Release qualification

Date: 2026-07-30

## Scope

Controller A exported a meaningful retained HPT range to `USB08_8G` while
running the final Release firmware. This specimen rejects SCSI SYNCHRONIZE
CACHE with valid ILLEGAL REQUEST sense and therefore must select the bounded
compatibility durability path.

## Identity

- Controller assembly: `1751136`
- J-Link serial: `69664082`
- Release S-record SHA-256:
  `838645AF04F6718231AE892A7F2EB16EC6710A8354DA270A6601CFEAC8E6ABE9`
- SD protocol state: `6`
- SD CID valid: `1`
- Representative SD-sector read: `1`
- Raw SD CID: `035344535330384780976F0084018559`
- USB label: `USB08_8G`
- USB hardware serial: `20111009140821671DA2`

## Controller result

- Baseline USB media generation: `8`
- Baseline compatibility required/count: `0 / 4`
- Requested HPT range: `301739760..302169332`
- Actual HPT range: `301739760..302169300`
- Retained/selected/published records: `6979 / 6979 / 6979`
- Snapshot gaps / requested-range gaps: `0 / 0`
- Healthy/degraded records: `6979 / 0`
- HPT status / USB status / first USB failure: `0 / 0 / 0`
- Terminal state: published, complete, USB phase `14` (complete)
- HPT staging: `8.90 s`
- USB publication, compatibility wait, and fresh verification: `26.99 s`
- Total: `35.90 s`
- File-write calls/bytes/max request: `11 / 350921 / 32768`
- Close / media flush / rename: `0.01 / 0.64 / 0.03 s`
- Post-export compatibility required/count: `1 / 7`
- Post-export USB media generation: `9`
- Fresh verification: `350921 / 350921` bytes
- Media handoff acceptance mask: `15`
- Live system errors: `0`

The compatibility count increased by three across the export's durability
flush points. The fresh session advanced the media generation, remounted with
the complete acceptance mask, and verified the entire published file. The
total was `9.89 s` longer than the preceding compliant-drive HPT export,
consistent with the intended 10-second unsupported-cache bound.

## Independent Raspberry Pi verification

The Pi identified the exact specimen as `/dev/sdc`, partition `/dev/sdc1`,
label `USB08_8G`, serial `20111009140821671DA2`.

- Unmounted `fsck.vfat -n -v` passed with no filesystem error:
  `8 files, 2232/1953804 clusters`.
- The volume was mounted read-only for inspection.
- Published file: `USB08_HPT.csv`
- Exact size: `350921` bytes
- SHA-256:
  `E7FE062565519B36DC2383D5B3C306162F6FFD2F9BF156A1021C4A677A6DB8F2`
- Completion trailer:
  `Export completion: COMPLETE; records published: 6979`
- The final data row is record `6979` at HPT timestamp `302169300`.
- No temporary export file was present.
- The volume was unmounted after inspection.

## Result

PASS. A real retained-range HPT export on `USB08_8G` selected the
ILLEGAL-REQUEST compatibility path, honored the 10-second bound, created and
verified a fresh USB session, and survived independent FAT, size, completion
trailer, and hash inspection.
