# Node 1 Hardware Layout

## pve1 as built (current reality)

`pve1` is an ASUS PN53 mini PC (Ryzen 7 7735HS, 32GB RAM), not the
dedicated-server hardware the target design below assumes:

- **Disks**: 2x 2TB NVMe (Crucial CT2000E100SSD8), both in a single ZFS
  mirror (`rpool`) that serves as both the boot pool and VM storage
  (`local-zfs` = `rpool/data`). No spare disks to earmark for Ceph — the
  chassis only has 2 NVMe slots.
- **Network**: one physical NIC (Realtek RTL8125, 2.5GbE), bridged as
  `vmbr0`. No second NIC for a dedicated corosync/Ceph link. (An unused
  `nic1` stanza in `/etc/network/interfaces` is a leftover from the
  installer template — there is no second NIC on this hardware.)

This is sufficient and correct for **Stage 1** (see `00-overview.md`) —
base config and hardening don't need split disks or multiple NICs. It is
*not* sufficient for **Stage 2** (Ceph/HA) as designed below without
either different hardware or a materially different plan (e.g.
USB/Thunderbolt-attached OSD storage, which trades away the
enterprise-SSD/PLP guidance below — not recommended, revisit when
actually provisioning nodes 2/3). Treat everything from here down as the
Stage 2 target design for purpose-built hardware, not a description of
`pve1`.

## Target design (Stage 2, future dedicated hardware)

Build node 1 so nodes 2/3 are drop-in identical later — don't re-architect
disks or network when the cluster grows.

## Disks — two roles, physically separate devices

1. **Boot/OS pool (`rpool`)** — 2x small SSDs (240-480GB plenty), ZFS
   mirror. Proxmox itself only. Never share with Ceph OSDs.
2. **Future Ceph OSD disks** — must end up as raw, unformatted devices —
   no ZFS/RAID/LVM underneath (Ceph does its own replication; anything
   underneath just doubles copy-on-write/checksumming and hurts
   performance). Use enterprise SATA/NVMe SSDs with power-loss protection
   (PLP) — matters far more for Ceph write latency than for general ZFS
   use. Ceph needs 3 nodes minimum to go live, so on node 1 these disks
   either sit idle or run as a temporary local ZFS pool (all VMs live
   here until nodes 2/3 exist), to be wiped and handed to Ceph once the
   cluster can actually run it. See `02-storage-zfs-ceph.md`.

No permanent local-ZFS "replicated tier" — once Ceph is live, it's the
only HA storage; local ZFS is boot pool + this temporary pre-Ceph staging
role, not an ongoing parallel tier. Avoid consumer QLC SSDs for either
role — Ceph punishes it on latency, ZFS on sync writes/scrub.

## Networking — cable and provision for the final topology now

Logically separate networks (ideally separate NICs/VLANs):

- **Management** — web UI / SSH
- **Corosync** — cluster quorum traffic, low-latency, unshared
- **Ceph public** — VM-to-OSD traffic
- **Ceph cluster/backend** — OSD-to-OSD replication (heaviest load)

Practical layout: 2x 10/25GbE bonded or split — one pair for Ceph, one
for mgmt + corosync + VM traffic, with corosync on its own VLAN even if
sharing a physical NIC. Get switch/cabling right on node 1 so nodes 2/3
are identical drops.

## CPU / RAM sizing

Size for the end state, not day one — RAM is the hardest thing to
retrofit. Budget covers:

- OS + ZFS ARC (ZFS wants RAM, not just disk)
- Ceph OSD daemons — realistically 3-5GB per OSD once running
- Actual VM workloads

Roughly a core per OSD on top of what VMs need. If OSDs won't be active
for a while, that's headway, but buy for 3 nodes' worth of eventual OSD
load.

## Backup target (PBS)

Keep it off the Ceph/compute nodes if possible — its failure domain
should be independent of the cluster. Modest separate machine or NAS:
ZFS mirror or raidz2, ECC RAM if possible, capacity for retention policy.
If it has to run as a VM inside the cluster short-term, that's a known
compromise, not the end state.

## Node 1 install sequence

1. Install Proxmox VE fresh onto the ZFS boot mirror.
2. Provision the Ceph-earmarked disks as a temporary local ZFS pool and
   run all VMs from it (or leave idle if VMs aren't moving over yet).
3. Once nodes 2/3 join and Ceph goes live: wipe this pool, hand the disks
   to Ceph, migrate VMs onto Ceph-backed storage.