PVE cluster formation: MK33/MK34/MK39 as pve-swarm. NFS active. HA groups configured. N150 corrected.

PRD Drafts/pve-three-node-ha-cluster.md

@@ -0,0 +1,139 @@
+# PVE 3-Node HA Cluster for Iron Legion
+
+**Status:** Draft | **Author:** Artemis | **Date:** 2026-06-04
+
+## 1. Objective
+
+Configure MK33, MK34, and MK39 as a Proxmox VE 3-node cluster with shared NFS storage from TrueNAS. Enable manual live migration of VMs/LXCs between nodes, and optionally automatic HA failover for critical workloads.
+
+## 2. Current State
+
+| Node | CPU | RAM | Storage | Role |
+|------|-----|-----|---------|------|
+| MK33 (Silver Centurion) | Intel N150 4c/4t | 16GB | Local SSD | PVE HA |
+| MK34 (Southpaw) | Intel N150 4c/4t | 16GB | Local SSD | PVE HA |
+| MK39 (Gemini) | Intel N150 4c/4t | 16GB | Local SSD | PVE HA (spare)
+| TrueNAS SCALE | 4c | 11GB | HDD pool | NFS server |
+
+All nodes on `192.168.0.0/18`. TrueNAS at `192.168.16.254`.
+
+## 3. Architecture
+
+### 3.1 Cluster Model: Proxmox 3-Node Cluster (No Ceph)
+
+```
+MK33 (192.168.7.33) ──┐
+                       ├─ Corosync Ring ── Shared NFS (TrueNAS)
+MK34 (192.168.7.34) ──┤
+                       │
+MK39 (192.168.7.39) ──┘
+```
+
+- **Quorum:** 3-node cluster = 2 votes needed for quorum. If one node dies, remaining 2 form quorum.
+- **Shared storage:** TrueNAS NFSv4.2 export `/mnt/Ice/Backup`
+- **HA manager:** Proxmox HA services (`pve-ha-crm`, `pve-ha-lrm`) for automatic restart
+
+### 3.2 Storage Flow
+
+```
+Build on local disk → Test workload → Shutdown → Move disk to NFS → Restart on NFS
+                                          ↓
+If node fails: HA manager detects → Restarts VM/LXC on surviving node (same NFS disk)
+```
+
+### 3.3 Workload Planning
+
+| Type | Count per node | Resources each |
+|------|---------------|----------------|
+| VM (general) | 1 | 4 vCPU, 4096 MB RAM |
+| LXC (lightweight) | 5–10 | 1 vCPU, 512–1024 MB RAM |
+
+**Total per node estimated:** 9–14 vCPUs (but N100 is 4c/4t — LXCs share cores opportunistically via cgroups)
+**Total RAM per node:** VM 4GB + 5×1GB LXCs = ~9GB allocated, 7GB headroom
+
+## 4. Pros vs Cons
+
+### 4.1 3-Node Cluster (Recommended)
+
+**Pros:**
+- Unified web UI for all 3 nodes from any one node
+- Live migration of VMs/LXCs between nodes (zero downtime)
+- Automatic HA failover for critical VMs/LXCs
+- Quorum maintained with 2 of 3 nodes online
+- Shared NFS storage means VMs are portable across nodes
+
+**Cons:**
+- Corosync ring traffic adds minor network overhead
+- If 2 nodes fail simultaneously, quorum lost, cluster stops
+- HA failover is restart (brief downtime), not live migration
+- N100 CPU is modest — 3 VMs + 15 LXCs across cluster is tight but workable
+
+### 4.2 Standalone Nodes (Current)
+
+**Pros:**
+- Simple, no cluster complexity
+- Node failure doesn't affect others
+- No Corosync network overhead
+
+**Cons:**
+- No live migration — moving a VM requires export/import
+- No automatic failover — manual intervention if node dies
+- 3 separate web UIs to manage
+
+## 5. Implementation Plan
+
+### Phase 1: Cluster Formation
+
+1. Add all 3 nodes to `/etc/hosts` on each node (or DNS via Technitium)
+2. On MK33: `pvecm create iron-legion`
+3. On MK34/MK39: `pvecm add 192.168.7.33`
+4. Verify: `pvecm status` shows 3 nodes, quorum 2/3
+
+### Phase 2: NFS Storage Setup
+
+1. Ensure TrueNAS exports `/mnt/Ice/Backup` with:
+   - NFSv4.2
+   - `maproot` or `mapall` to `root` (PVE nodes need root access)
+   - ACL allows `192.168.0.0/18`
+2. On PVE Datacenter → Storage → Add → NFS:
+   - ID: `truenas-backup`
+   - Server: `192.168.16.254`
+   - Export: `/mnt/Ice/Backup`
+   - Content: `images,rootdir`
+3. Verify storage shows on all 3 nodes
+
+### Phase 3: HA Configuration
+
+1. Proxmox HA → Add groups:
+   - `critical`: nodes mk33,mk34,mk39 (any node)
+   - `local-only`: single-node constraint for local-disk VMs
+2. For each VM/LXC on NFS storage:
+   - Datacenter → HA → Add → Select VM → Group `critical` → Start on any
+3. Start fencing daemon if IPMI/ watchdog available (optional for N100)
+
+### Phase 4: Workload Migration Testing
+
+1. Build a test LXC on local storage
+2. Migrate disk to NFS: `Move disk` → target `truenas-backup`
+3. Verify LXC starts from NFS
+4. Test live migration: right-click → Migrate → select target node
+5. Test HA failover: power off source node, verify restart on surviving node
+
+## 6. Open Questions
+
+1. Do we need HA fencing? (IPMI not available on N100 — watchdog only)
+2. Should we reserve one node as "management" and only run LXCs on two?
+3. What's the Tailscale story — do we bind Corosync to LAN only or also Tailscale?
+
+## 7. Decision Points
+
+| Decision | Option A | Option B |
+|----------|----------|----------|
+| Cluster type | 3-node with quorum (recommended) | 2-node + witness (not recommended) |
+| HA level | Manual migration only | Full HA with auto-restart |
+| Storage | NFS only (current) | Add local Ceph later |
+| Resource reserve | 1 node mostly idle | Distribute evenly |
+
+---
+
+**Awaiting Commander Bobby review and approval.**