# Overview & Roadmap

## Background

Current hardware requires disabling KVM hardware virtualization for VMs to
start at all (falls back to software emulation — slow). This is a
host/BIOS-level issue, not a Proxmox limitation, and shouldn't be needed on
new hardware. Before reusing that workaround on the new box:

- Confirm VT-x (Intel) / AMD-V (AMD) is enabled in BIOS/UEFI.
- Confirm IOMMU is enabled if passthrough is planned.
- Update BIOS/microcode first.
- Rule out running Proxmox nested inside another hypervisor.

## End goal

3-node Proxmox VE cluster with HA-managed VMs. Two ways to get VM disks
available on more than one node (see `02-storage-zfs-ceph.md`):

1. **Ceph** — true distributed shared storage, sync replication, needs 3+
   nodes and a fast dedicated network. Zero/near-zero RPO on failover.
2. **ZFS + storage replication** — local ZFS pool per node, Proxmox
   replicates VM disks between nodes on a schedule (as often as every
   minute). Lighter weight, async — failover loses whatever changed since
   last replication.

Starting point: ZFS + replication (lighter, works from node 1 onward).
Ceph is the upgrade path once 3 nodes exist and/or zero-RPO failover
matters enough to justify the overhead.

## Cluster fundamentals (apply from node 1 onward)

- 3 nodes minimum for real quorum. If starting with 2, add a QDevice
  (small VM or Raspberry Pi) as tie-breaker.
- Dedicated network for corosync (cluster/quorum traffic) — never shared
  with VM or storage traffic. Needs low, consistent latency (well under
  5ms); jitter matters more than bandwidth.
- All nodes on the same PVE version, NTP-synced, SSH reachable between
  nodes.
- Set VM CPU type to a portable type (e.g. `x86-64-v2-AES` or `kvm64`)
  rather than `host` if nodes will ever have different CPUs — needed for
  clean live migration.

## Rollout sequence

1. Build node 1 per `01-hardware-node1.md` — fresh PVE install on ZFS boot
   mirror, local ZFS "tier 2" pool for VM disks, Ceph-earmarked disks left
   idle or as a temporary ZFS pool.
2. Migrate VMs off old hardware via `vzdump` → copy backups → `qmrestore`
   onto the new ZFS storage (converts disks to ZVOLs).
3. Apply hardening (`04-security-hardening.md`) and networking
   (`03-networking.md`) before exposing the node beyond the LAN.
4. Add nodes 2 and 3 identically (same disk/network layout).
5. Join cluster, stand up dedicated corosync network, configure
   replication and HA groups.
6. Optionally migrate the Ceph-earmarked disks from temporary ZFS to real
   Ceph OSDs once 3 nodes are up.