# clar200-unlock

Unlock two EMC/CLARiiON-locked Seagate **Exos X18** SAS drives
(ST16000NM004J, fw ES2264 — SN **ZRS015V7**, **ZR511KWK**) via the Seagate
**F3 service terminal**, using an **ESP32-C3** as a 3.3 V USB-serial bridge.

Goal: turn two 16 TB paperweights into healthy 512-byte-sector disks for the
`tank` ZFS pool, which is short on 14.6 TB+ spares (mirror-35 has a dead + a
dying leg; ex-mirror-38 is a bare single-disk vdev).

## Why this exists

These drives answer SCSI INQUIRY/VPD but return `Hardware Error / Internal
target failure` to **every** other command — including READ CAPACITY — so no
host-side tool (sg_format, openSeaChest, SeaChest, firmware download) can format
them. Full prior evidence: `~/bin/EMC_CLAR200_DRIVE_FIX_NOTES.md`. The F3 UART
bypasses the SCSI layer; it's the only remaining DIY lever.

## Layout

| Path | What |
|---|---|
| `PROCEDURE.md` | **Start here** — the physical + operational runbook (bench, wiring, flash, F3 entry, format, verify) |
| `firmware/clar200_bridge.ino` | ESP32-C3 transparent USB↔UART bridge sketch (live baud menu) |
| `firmware/flash.sh` | One-command build + flash from steel141 (`/dev/ttyACM0`) |
| `docs/f3-command-reference.md` | F3 dialect — confirmed vs. 7200.11-era-only; what to verify with `?` |
| `IDEA.md` / `DECISIONS.md` / `CLAUDE.md` | project brief / decisions / Claude Code context |

## Hardware (current)

- **ESP32-C3** on steel141 `/dev/ttyACM0` (native USB-Serial-JTAG, 3.3 V, MAC
  `58:8c:81:ac:f0:4c`). 3.3 V is a native match for the F3 header — no separate
  USB-TTL adapter needed.
- **Target drive** ZRS015V7 currently in a pve173 JBOD → must be **benched** for
  F3 work (never in-chassis next to live tank).

## Quickstart

```bash
cd firmware && ./flash.sh /dev/ttyACM0   # build + flash the bridge
screen /dev/ttyACM0 115200               # open it; ~1/~2/~3/~4 set DRIVE baud
```
Then follow `PROCEDURE.md` from Step 2 (bench the drive).

## Status

Bootstrapped 2026-06-14. Firmware + procedure written; **not yet flashed, drive
not yet benched.** See the latest `.claude/handoffs/` entry.