jakman85
49d82491dd
I framed this as an OPEN HARDWARE FAULT and blamed, in order: the DIMM, BIOS memory remapping,
and stale Fast Boot memory-training data. ALL THREE WERE WRONG. The hardware is fine.
ROOT CAUSE: HP's R21 firmware publishes a CORRUPT EFI Memory Attributes Table, and Linux 6.12
fails to validate it before reserving memory from its contents. drivers/firmware/efi/memattr.c
never validates num_entries or desc_size:
if (tbl->version > 2) { pr_warn(...); goto unmap; }
tbl_size = sizeof(*tbl) + tbl->num_entries * tbl->desc_size;
memblock_reserve(efi_mem_attr_table, tbl_size);
Garbage version > 2 -> kernel bails, memory intact. Garbage version <= 2 -> kernel multiplies two
garbage fields and reserves GIGABYTES from the table address to the top of RAM.
THE EVIDENCE THAT SETTLES IT: the same machine — same DIMM, same BIOS, same kernel, same cmdline —
booted with the FULL 15.9 GiB two boots earlier, with a byte-identical BIOS-e820 map. Boot -2:
15,917,744K available, 615,208K reserved, 'Unexpected EFI Memory Attributes table version
1463964749'. Boots -1/0: 2.6 GiB, 13.9 GiB reserved, 'Failed to map ... @ 0xbeeb0018'. No hardware
fault is intermittent in that shape or fixed by a reboot. MemTotal = DMA(3840) + DMA32(684481)
pages = 2,753,284 kB exactly, Normal contributing zero.
BOTH PROD NODES ARE AFFECTED. k3s-prod-1 prints 'Unexpected EFI Memory Attributes table version
1030' — also garbage, but >2, so the kernel bails and it keeps its 32 GiB BY LUCK, NOT IMMUNITY.
It is one unlucky boot from the identical fault. Dev nodes publish no memattr table at all
(Proxmox OVMF) and are unaffected.
FIX: kernel >= 6.13 — upstream 8fbe4c49c0cc 'efi/memattr: Ignore table if the size is clearly
bogus', whose commit message describes this verbatim. Verified absent from v6.12 and from current
linux-6.12.y. On Debian 13: linux-image-amd64 from trixie-backports.
DO NOT buy RAM, move the DIMM, RMA the board, or run memtest expecting failures. Rebooting,
disabling Fast Boot, clearing CMOS and unplugging USB are all the same lottery — they move where
the table lands and may LOOK like fixes.
Records every killed hypothesis with its disproof so none of them get re-run.
Serves: R-ENV-01, R-ENV-03. Task: T-7.1.
infra/ — node provisioning and the toolchain
OpenTofu (Proxmox VE) + cloud-init + Ansible bring up the 3-node k3s/Cilium dev cluster.
Spec: ../home-network-k3s/docs/02-environments-and-provisioning.md.
| Path | What |
|---|---|
tofu/ |
The "Create" stage: 3 cloud-init'd VMs on the Proxmox box (bpg/proxmox provider) |
cloud-init/ |
First-boot baseline shipped as a Proxmox user-data snippet |
ansible/ |
The "Baseline"/"Configure" stages: k3s HA, Cilium, kube-vip, the VPN egress gateway |
devcontainer/ |
The pinned toolchain (tofu, ansible, sops, age, flux, kubectl, helm and the whole CI gate toolchain) |
cluster.sh |
RETIRED — drove the old libvirt VMs; does not work against Proxmox |
PHASE1-STATUS.md |
Current state of the cluster and how to reconnect to it |
PHASE1-SCOPE.md |
Historical Phase-1 scoping doc (libvirt era — superseded) |
Where the cluster actually lives
The dev cluster is not on this workstation. It runs on a Proxmox VE host; the nodes sit on the Proxmox LAN and are reached across a pfSense NAT:
| Nodes | k3s-dev-1/2/3 at 192.168.1.50/.51/.52 — 6 vCPU, 24 GiB, Debian 13, k3s v1.36.4 |
| kube-API | kube-vip VIP 192.168.1.49:6443, reached from the workstation via NAT 192.168.2.50:6443 |
| Node SSH | pfSense NAT 192.168.2.102:2250/2251/2252 → node :22 (Ansible only) |
| Ingress VIP | 192.168.1.53 (Cilium L2, shared Gateway); .53–.60 reserved for LB VIPs |
The earlier libvirt/KVM cluster on 10.73.0.0/24 is retired. Any doc or command referencing
virsh, qemu:///system, or 10.73.0.x for the cluster is historical.