# USB09 Pi pretest health

Status: complete
Type: evidence
Updated: 2026-08-01
Next Action: none; retain as historical pretest evidence for the resolved USB09 incident

Project Map: work/maps/map-smi-firmware-stabilization-and-qualification.md
Workpackage: work/wp/completed/wp-restore-broad-usb-compatibility-baseline.md
Checklist: work/checklists/checklist-stage-1b-four-drive-usb-compatibility-baseline.md
Incident: work/incidents/incident-usb09-false-write-failure-and-usb-compatibility-architecture-correction.md

## Identity and state

The Raspberry Pi identified the incident specimen without ambiguity:

- canonical label `USB09`;
- FAT UUID `24E4-9846`;
- General UDisk serial `2512300955508200677718`;
- 15,728,640 logical blocks at 512 bytes, totaling 8,053,063,680 bytes;
- one FAT32 partition, unmounted before and after the checks.

These values match the reformatted USB09 identity recorded by the incident.
Linux device name `/dev/sdc` was session-local and is not used as the durable
identity.

## Read-only health gate

- `fsck.fat -n -v` reached the final filesystem sector, found two FATs, and
  reported 5 files using 16 of 245,631 data clusters with no structural
  corruption. It repeated the benign Windows-format notice that the volume
  label is stored in the root directory rather than the boot-sector label
  field and explicitly left the filesystem unchanged.
- A direct, unmounted read covered all 8,053,063,680 device bytes in 227
  seconds at approximately 35.5 MB/s. `dd` returned `0`.
- `sg_readcap` independently reported the same final LBA, logical-block size,
  block count, and total capacity.
- A read-only mount enumerated and hashed all files. The prior incident export
  `SMI6_07162026_20260725t0836-20260730t1541.csv` remained 374,707 bytes with
  SHA-256
  `D675AF49DDE995139EE12E734570E76D7D33AD5F95C3FD310876C0243821B951`,
  exactly matching the historical evidence.
- The kernel logged no USB reset, SCSI sense, medium, device-offline,
  buffer-I/O, or block-I/O error during enumeration, the complete read, or the
  read-only content check.

## Disposition

USB09 passes the same non-destructive Pi pretest gate used for the four-drive
baseline and is unmounted. This proves present media readability and FAT
consistency; the Controller A production workflow and independent post-export
Pi validation remain the incident-regression gate.
