# ks2 decommission — summary plan

Goal: release `ks2.lutran.fr` (`164.132.173.57`, SSH :2233, host
`ns3247221`) once ks4 has a real 3-2-1 backup without it.
**Deadline: rental ends Sep 30, 2026.**

## What ks2 does today (updated 2026-08-28)

**Nothing is written to ks2 any more.** Both feeds are retired: the
`01:00` replica push (replaced by the local leg on ks4's sdb5 pool,
[local-backup-cron.md](../ks4/local-backup-cron.md)) and the `04:00`
`incus-backup.sh` rsync (replaced by restic → S3,
[restic-backup.md](../ks4/restic-backup.md)).

What remains on the box is **cold history**: instance replicas on pool
`data` (last refreshed 2026-08-09) and the rsync tree
`/backup/ns3061243` on pool `backup` (last refreshed 2026-08-28),
snapshotted daily there (`zfs-auto-snapshot.sh`, 2-month expiry).

⚠️ While the nas leg waits for FTTH, instances have no *fresh*
off-site copy — the ks2 push is to be re-enabled as soon as the
initial restic sync finishes (decided 2026-08-28), and retired again
when nas takes over. (The leg moved from nuc to the new host `nas`
on 2026-08-30 — see [nas-seed.md](nas-seed.md).)

## Inventory findings (2026-08-22)

- `biwiki` exists only on ks2, `spot` only on ks2 + ks4's `backup`
  project — **decision: both abandoned**, safe to delete from backups.
- `incus-backup.db` is stale (lists `spot`, misses `livetrail`,
  `outline`, `login`, …) — forgotten-manifest drift is exactly what
  the replacement had to eliminate — restic's drivers back up *all*
  instances and auto-discover *all* databases, opt-out instead of
  opt-in.
- `livetrail` (running on ks4) is **absent from ks4's local `backup`
  project** — the local leg was run manually once and never again;
  automating its cron fixes this.
- Both ks4 backup crons were **commented out — no ks4 backup ran at
  all** (hence the stale ks2 rsync data: dirs `Jul 23`, incus dumps
  `Aug 9`). Fixed 2026-08-22 — see
  [local-backup-cron.md](../ks4/local-backup-cron.md).
- `/backup/ns3061243` also holds pre-2023 dirs (`catc`, `mythoughts`,
  `qcm`) — those instances still exist stopped on ks4, so nothing
  unique expected there; spot-check before wiping.
- Losing ks2 also loses its 2 months of rsync-snapshot history —
  acceptable: restic keeps 14 daily / 8 weekly / 6 monthly.

## Target architecture (3-2-1 for ks4)

| Leg | Mechanism | Status |
|---|---|---|
| local, 2nd disk | `incus-copy.sh -p backup -s backup` → sdb5 pool | **live** (01:00) |
| off-site, S3 (data+DB) | **restic** → bucket `restic-data` ([restic-backup.md](../ks4/restic-backup.md)) | **live** (05:00) |
| off-site, S3 (instances) | restic over `incus file mount` of the `backup`-project replicas | **shelved** 2026-08-28 (replication covers instances) |
| off-site, nas | **nas** pulls `ks4:*` → pool `ks4backup` over WG ([nas-seed.md](nas-seed.md)) | waiting FTTH (< Sep 30); moved off nuc 2026-08-30 |
| off-site, ks2 (interim) | `incus-copy.sh -d ks2 -m push` at 02:00 until the nas leg seeds | to re-enable once the restic seed finishes |

## Actions (backup work documented in [`../ks4/`](../ks4/), ks2-only tasks here)

1. ~~salvage biwiki/spot~~ — decided 2026-08-22: both abandoned,
   **deleted** from ks2 and ks4's `backup` project
2. ~~[local-backup-cron.md](../ks4/local-backup-cron.md)~~ — **done
   2026-08-22**: leg 1 cron re-enabled, ks2 rsync kept as stopgap;
   `livetrail` verified present in the `backup` project
3. ~~first S3 leg~~ → **restic** is the S3 tool
   ([restic-backup.md](../ks4/restic-backup.md), live 2026-08-28; the
   predecessor's doc is kept as reference)
4. ~~instance leg to S3~~ — **shelved 2026-08-28**: instances are
   protected by replication (sdb + nas/ks2), their data and configs by
   `restic-data`
5. [nas-seed.md](nas-seed.md) — **prepared**; after FTTH: seed the nas
   pull leg, verify all instances, test-restore one
6. [decommission.md](decommission.md) — **prepared**; cut flows,
   final diff of `/backup/ns3061243`, wipe pools, terminate at OVH

## Release gates — ks2 can be dropped only when

- [x] biwiki + spot consciously abandoned (2026-08-22)
- [x] local leg cron running since 2026-08-22, **18/18 instances**
      replicated (verified 2026-08-28)
- [ ] **nas** leg fully seeded **and** one instance test-restored
- [x] restic S3 backups live (05:00) **and** restore drill passed
      2026-08-28: tree restored byte-identical to live, dump restored
      and loaded into a scratch MariaDB (12/12 tables)
- [ ] ks4 crons pointing at ks2 disabled