# platform/longhorn

**Longhorn** — distributed replicated block storage across the 3 nodes.

- **Governing ADR:** [ADR-0003 — Distributed storage: Longhorn (+ bulk tier + Velero)](../../../home-network-k3s/decisions/adr-0003-storage-longhorn.md)
- **Spec:** [docs/04 — Storage & State](../../../home-network-k3s/docs/04-storage-and-state.md)
- **Serves:** R-STATE-01..04
- **Owner:** WS-STORAGE

## What this stub is

Flux `HelmRelease` + two `StorageClass`es:
- **`longhorn`** — the **default**, **3-replica** replicated class (replica count is the
  `${LONGHORN_DEFAULT_REPLICA_COUNT}` overlay knob). Durable home for app/config state and KubeVirt
  VM disks (via CDI).
- **`bulk`** — non-replicated tier for large media (Plex library, download staging). **STUB**: its
  backing store is **OQ-2 (unresolved)** — escalate before finalizing. Plex's metadata DB stays on
  the 3-replica class regardless (ADR-0003).

## Contract (consumed by everyone with state)

Per `roadmap/workstreams.md`, WS-STORAGE exposes the `longhorn` (replicated) and `bulk` (media)
StorageClasses; WS-APPS/WS-VM/WS-OBS reference them from ServiceDefinitions. Do not place bulk media
on the replicated tier or app DBs on the bulk tier.

## TODO (later phases)

- **OQ-2 (human):** decide the bulk-tier backing (NAS/NFS vs dedicated disk). Blocks `bulk` finalize.
- **Phase 2 (WS-STORAGE):** dedicated Longhorn data disk path (docs/02); prove a PVC survives
  pod destroy/rebuild (R-STATE-01, Phase-2 exit gate).
- **Phase 4 (WS-STORAGE):** wire off-cluster backup target with Velero (R-STATE-03).