home-network-k3s-impl/infra/PROD-PROVISIONING.md

Prod bare-metal provisioning checklist (T-7.1)

Task: T-7.1 · Workstream: WS-INFRA · Serves: R-ENV-01, R-ENV-02, R-ENV-03, R-PLAT-01/03 Status: Phase 7 opened by the operator 2026-08-31 — prep only. Nothing is installed on prod hardware until the blockers in §7 are closed and make -C ci gate is green.

Entry-gate note (recorded, not waived). roadmap/phases.md gates Phase 7 on "Phases 1–6 proven in dev/test; operator declares prod hardware ready." The operator has declared hardware ready. The first condition is not met: conformance is 37/51, and the uncovered set includes R-ENV-01/02/03 — the very requirements this document serves. We proceed with prep work knowingly; see DECISIONS-LOG.md (2026-08-31 Phase-7 entry).

Prod is 3× mini-PC bare metal (spec docs/02). The dev path (OpenTofu → Proxmox VM → cloud-init) does not apply: there is no hypervisor API to call. Stage 1 "Create" is a human imaging a box. Stages 2–4 (baseline, cluster-join, manage) reuse the same Ansible roles and the same Flux base as dev — that reuse is the R-ENV-02 obligation.

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0. Node inventory

Fill a row per node as it lands. Node 1 is as-found on 2026-08-31.

	node 1	node 2	node 3
Hostname	k3s-prod-1	k3s-prod-2	k3s-prod-3
LAN IP	192.168.2.10	192.168.2.11	192.168.2.12
Model	HP EliteDesk 800 G5 Desktop Mini	HP EliteDesk 800 G5 Desktop Mini	HP EliteDesk 800 G5 Desktop Mini
CPU	i7-9700T, 8c/8t, VT-x	i7-9700T, 8c/8t, VT-x	i7-9700T, 8c/8t, VT-x
RAM	31 GiB (2×16 GB Micron)	2.6 GiB usable of 16 GB — see §0b	31.1 GiB usable of 32 GB (2×16 GB Crucial CT16G4SFD8266.C16FE, a matched pair)
Disks	1× 477 GB SATA SSD (C400-MTFDDAC512M, ~2011)	1× 477 GB NVMe (PM9A1 Samsung)	1× 466 GB SATA SSD (WDC WDS500G2B0A-00SM50)
Drive health	69% life, 15 grown bad blocks, 187 erase fails	96% life, 2142 h, PASSED	100% life, 3213 h, PASSED, 0 grown bad blocks / 0 erase / 0 program fails, 0 CRC
OS	Debian 13 (trixie), kernel 6.12	Debian 13 (trixie), kernel 6.12	Debian 13 (trixie), kernel 6.12.107+deb13-amd64
Firmware	HP R21 Ver. 02.26.00	HP R21 Ver. 02.26.00	HP R21 Ver. 02.26.00
/dev/kvm	present	present	present
Serial	MXL1052NGN	MXL0073949	8CC015307N

Node 1's DIMMs are also not a matched pair (surfaced 2026-09-01 by the new health check; unrelated to §0b and not a fault): DIMM1 is a Micron 8ATF2G64HZ-3G2E1 (DDR4-3200), DIMM3 a Micron 16ATF2G64HZ-2G6E1 (DDR4-2667). Both are 16 GB so capacity is correct, but they differ in rank organisation and rated speed, so the pair runs at the slower 2667. Recorded only because §2 requires the three nodes to end up symmetric, and "2×16 GB Micron" hid the mismatch.

The nodes are NOT hardware-symmetric — and with node 3 in (2026-09-03) the asymmetry is THREE-WAY, not a node-1 outlier. Node 1 has a ~2011 SATA SSD with real wear; node 2 a healthy modern NVMe; node 3 a third distinct model, a WD Blue 3D SATA SSD in excellent health (100% life, 0 grown bad blocks). Three nodes, three different drive models, and only one is NVMe. §2 requires an identical disk layout across all three because Longhorn replica placement assumes symmetry — so this is a live input to the disk decision, not a footnote. Node 2's NVMe is the drive node 1 should have had; node 3 does not have it either. Node 3 is also the only node with two matched DIMMs (2× Crucial 2Rx8 DDR4-2666) and the only one with its full RAM complement of 32 GB actually usable. That is luck, not immunity: node 3's firmware publishes an EFI Memory Attributes Table too (MEMATTR=0xbeece018), the kernel simply parsed it cleanly on this boot, so node 3 is exposed to the §0b bug on exactly the same terms as node 1 and needs the same >= 6.13 kernel. Node 3 therefore WIDENS §0b's blast radius from "both prod nodes" to all three; it is not a control machine. Every node also carries exactly one physical disk with no unpartitioned spare, so node_baseline_longhorn_device / node_baseline_etcd_device have nothing to claim on any of the three without repartitioning or adding drives — the §2 decision cannot be satisfied by node 3 either.

Dev nodes for comparison: 8 vCPU / 24 GiB / Debian 13, two dedicated data disks (Longhorn + etcd).

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0b. SOLVED — a Linux kernel bug, NOT a hardware fault (2026-09-01)

This section previously read "OPEN HARDWARE FAULT" and blamed the DIMM, then BIOS memory remapping, then stale Fast Boot memory training. All three were wrong. The hardware is fine. Keeping the correction visible because the wrong framing nearly cost money and a board RMA.

k3s-prod-2 intermittently addresses only ~2.6 GiB of its 16 GB. Root cause: HP's R21 firmware publishes a CORRUPT EFI Memory Attributes Table, and Linux 6.12 fails to validate it before reserving memory based on its contents. Fixed upstream in 6.13.

The evidence that breaks it open

The same machine — same DIMM, same BIOS, same kernel, same cmdline — booted with the full 15.9 GiB two boots earlier:

Boot	Memory: … available	reserved	memattr line
−2	15,917,744K	615,208K	Unexpected EFI Memory Attributes table version 1463964749
−1	2,613,912K	13,913,856K	Failed to map EFI Memory Attributes table @ 0xbeeb0018
0	2,568,544K	13,958,980K	Failed to map EFI Memory Attributes table @ 0xbeeb0018

The BIOS-e820 map is byte-identical across all three. No hardware fault is intermittent in that shape, and none is fixed by a reboot.

Mechanism (verified against kernel source)

drivers/firmware/efi/memattr.c, v6.12 and current linux-6.12.y:

if (tbl->version > 2) { pr_warn("Unexpected EFI Memory Attributes table version %d\n", ...); goto unmap; }
tbl_size = sizeof(*tbl) + tbl->num_entries * tbl->desc_size;
memblock_reserve(efi_mem_attr_table, tbl_size);

num_entries and desc_size are never validated. With a corrupt table:

• garbage version reads > 2 → kernel warns and bails → memory intact (the lucky path)
• garbage version reads ≤ 2 → kernel multiplies two garbage fields and memblock_reserve()s the product — gigabytes, from the table address to the top of RAM (the unlucky path)

That accounts for every observation: Normal zone present 3340288 / managed 0, and MemTotal = DMA (3840) + DMA32 (684481) pages = 2,753,284 kB exactly, with Normal contributing zero.

ALL THREE prod nodes are affected — none is immune

Seven boots observed across the three machines. The MAT address moves boot-to-boot on every node with settings held constant, and each node has been seen on more than one path:

Node	Boot	MEMATTR=	Kernel's read	Memory
1	−1	0xbeee6018	(no message — table read as VALID)	32.4 G ✅
1	0	0xbeec9298	version 1030 (> 2 → bail)	32.4 G ✅
2	−2	0xbeadc018	version 1463964749 (> 2 → bail)	15.9 G ✅
2	−1	0xbeeb0018	Failed to map	2.6 G ❌
2	0	0xbeeb0018	Failed to map	2.6 G ❌
3	−1	0xbee8a018	version 1463964749 (> 2 → bail)	32.4 G ✅
3	0	0xbeece018	(no message — table read as VALID)	32.4 G ✅

So there are three outcomes, not two: bail-out on a garbage version > 2, a valid parse with a sane size, and the catastrophic path. k3s-prod-3 publishes a MAT at 0xbeece018 exactly like the others — the absence of a memattr diagnostic line on its current boot means the kernel read a valid table, which is the opposite of immunity. Dev nodes publish no MAT at all (Proxmox SeaBIOS/OVMF) and are genuinely unaffected.

All three prod nodes are on the same lottery and all three need the ≥ 6.13 kernel.

The corrupting bytes are the OS boot chain, not the firmware or the DRAM

The garbage version 1463964749 = 0x5742544D appeared on node 2 AND node 3 — two different machines, identical corrupting bytes. That rules out both firmware-specific behaviour and a DRAM fault: the overwriter is the shared OS boot chain (shim / GRUB / EFI stub / initrd placement), writing the same data into the page the firmware pointed at. This is the documented failure mode — the firmware places the MAT in memory the OS classifies as plain System RAM, and whoever allocates there next overwrites it.

It also means the boot chain's own allocation footprint — initrd size, module set, boot device — is part of the causal chain, which matters for the experiment design below.

Mechanism, traced to the byte (second, independent confirmation)

A second research pass reached the same root cause by a different route and pinned the arithmetic:

• The garbage version node 2 read was 1463964749 = 0x5742544D = the ASCII bytes MTBW. The kernel is reading unrelated data, not a table. HP publishes the MEMATTR pointer into memory that /sys/firmware/memmap calls plain System RAM, so the pre-Linux boot chain overwrites it.
• tbl_size is a signed int. num_entries * desc_size is u32 * u32, wraps mod 2^32, and when bit 31 lands the result is negative.
• memblock_reserve(base, tbl_size) converts that negative int to phys_addr_t, sign-extending to ~0xFFFFFFFF_xxxxxxxx; memblock_cap_size() clamps it to PHYS_ADDR_MAX - base. Every physical address above 0xbeeb0018 is reserved.
• memblock_free_all() then hands the buddy allocator nothing above that line, while present_pages (which comes from memblock.memory) is untouched — producing present 3340288 / managed 0.
• The Failed to map EFI Memory Attributes table message is emitted later, by efi_memattr_apply_permissions(), whose memremap() of the absurd size fails. That message is therefore positive proof the reservation already happened — it is a consequence, not the cause.

The cleanest A/B tell between the two nodes is one line of dmesg:

	NODE_DATA(0) allocated	meaning
prod-2 (bad)	[mem 0xbee85680-0xbeeaffff]	ends at 0xbeeb0000 — pgdat forced immediately below the reservation
prod-1 (good)	[mem 0x82f7d5680-0x82f7fffff]	ends at 0x82f800000 — top of RAM, the normal placement

Identical 0x2a980 allocation size, opposite placement. Node 2's DMA32 managed is also 684481 vs node 1's 775777 on identical present — ~356 MiB of extra structures forced below 4 GiB.

THERE IS NO KERNEL CMDLINE WORKAROUND

efi_memattr_init() is called from efi_config_parse_tables() under only !CONFIG_X86_32 && efi_enabled(EFI_MEMMAP), and x86's efi_init() calls efi_config_init() before the efi_runtime_disabled() bail-out. So noefi, efi=noruntime and efi=novamap do not prevent the reservation. Booting a fixed kernel is the only real fix.

The fix

Boot a kernel ≥ 6.13 — upstream commit 8fbe4c49c0cc "efi/memattr: Ignore table if the size is clearly bogus" (Ard Biesheuvel, 2024-10-31, first released in v6.13), whose commit message describes this bug verbatim. Verified absent from v6.12 and from the current linux-6.12.y stable branch. On Debian 13 that means linux-image-amd64 from trixie-backports. A fixed kernel prints FW_BUG Corrupted EFI Memory Attributes Table detected! and keeps all the memory.

The hardening landed exactly one release too late for Debian 13: the bug has existed since the feature was introduced in 2016, 8fbe4c49c0cc first shipped in v6.13, and a follow-up 5d0faa8e8369 (2026-03-26) tightened it further to the current form, whose comment reads verbatim "This prevents a corrupted table from eating all system RAM." Debian's 6.12.107-1 demonstrably lacks it. Worth a Debian BTS report against src:linux — 6.12 is Debian 13's kernel for the release lifetime, and the fix is small and already upstream.

Same signature reported elsewhere: Ubuntu LP #2039382 (Dell, 16 GiB → 2.5 GiB, memtest clean, "fixed" by unplugging a USB mouse — which merely moved the table) and LP #1944019 (HP ZBook Studio G5, 16 GiB → 1.5 GiB).

Will 6.12 ever get the fix? — researched 2026-09-02. Not on its own.

Question	Answer
In linux-6.12.y today?	No. Newest commit touching memattr.c on that branch is 2024-07-12.
How long has it been available?	In mainline since v6.13, 2025-01-19 — ~19 months and ~97 6.12.y point releases.
Tagged Cc: stable?	No. Neither commit.
Tagged Fixes:?	No — and this is structural, not an oversight. The unvalidated arithmetic has been there since the file was created in 2016; it is not a regression, so there is no bad commit to point a Fixes: at. Both automatic feeds — the Fixes:-scanning scripts and AUTOSEL — had nothing to grab.
Picked up by AUTOSEL?	Never surfaced for any branch.
Has anyone asked?	No. Nothing on [email protected], and nothing in all 8,027 open+archived Debian bugs against src:linux. We would be first.
6.12 LTS horizon	EOL December 2028 — outlives Debian 13's own support window, so a backport is not time-barred.

Every automatic path has already had its chance and produced nothing. The probability that 6.12.y acquires this commit spontaneously is close to zero.

But the request is unusually strong, and the cost is one email. The decisive card: the cherry-pick is byte-clean. Debian trixie 6.12.94-1's drivers/firmware/efi/memattr.c hashes to 164203429fa7a…, identical to the upstream patch's pre-image blob — the file has not diverged at all between v6.12 and the commit's parent, so git cherry-pick 8fbe4c49c0cc applies with zero conflicts and zero adjustment. Neither the stable team nor Debian would have any backporting work to do, which removes the usual reason such requests are declined. The commit also meets every criterion in stable-kernel-rules.rst: in mainline, 17 insertions (limit 100 lines), fixes "a hardware quirk" and "a real bug that bothers people" — the enumerated categories.

Debian rebases, so an upstream pickup reaches us automatically: trixie carries linux 6.12.94-1 in trixie-security whose changelog opens "New upstream stable update: ChangeLog-6.12.91". No action beyond apt upgrade.

Plan

1. Run trixie-backports on both prod nodes now, as an explicitly provisional measure. Any 6.13+ kernel carries the fix. Record the standing cost: backports packages are provided as-is, without the main archive's security guarantees.
2. Email [email protected] — this is stable-kernel-rules.rst Option 2 for an already-merged patch. CC [email protected] and Ard Biesheuvel <[email protected]>, who both authored and committed the fix as EFI maintainer. Include: the commit ID and subject; 6.12.y only; the byte-clean-apply proof above (it pre-empts the main objection); and the reproduction — three consecutive boots on one machine, two outcomes, byte-identical BIOS-e820 across all three (the detail that proves the divergence is in the MAT, not the memory map), 16 GB → 2.6 GiB, plus a second identical machine taking the safe path only by chance. Attach both dmesgs. Corroboration exists: Ubuntu LP #1944019 (HP ZBook G5, 16 GiB → 1.5 GiB) and SUSE bugzilla 1231465, cited in the commit message itself.
3. File a Debian BTS bug as secondary, against src:linux via reportbug (the bug-script metadata is mandatory), severity important, referencing the lore thread. Debian's kernel handbook §9.1.7 allows cherry-picking a patch already accepted upstream — which this is, maintainer-authored with two Acked-bys — so if stable@ goes quiet Debian can act on its own.
4. Trigger to make the deviation permanent: no stable@ pickup within ~2 release cycles (4–6 weeks) and no Debian movement ⇒ encode the backports kernel in the provisioning IaC for every prod node and document it as a standing deviation from the distro baseline.

If patching by hand, only 8fbe4c49c0cc is needed. The follow-up 5d0faa8e8369 loosens a heuristic that was rejecting legitimate tables (false kexec warnings in Meta's fleet); it is not required for this symptom and depends on the first commit anyway.

Is it a BIOS setting? — three-way diff, researched 2026-09-03. No.

The operator's hypothesis, tested properly now that there are two working nodes and one broken one. All 240 attributes read on all three; identical key sets; identical firmware everywhere (same BIOS version string, ME 12.1.1.1022, GOP 9.0.1085, Super I/O 8.9.22). So every difference is settings or hardware, not firmware revision.

The discriminating set — both working nodes agree, the broken node differs. 26 attributes differ in total; after excluding per-machine noise (serials, UUIDs, MACs, asset tags, Born On Date, Feature Byte, SKU, memory size, storage device names) and settings falling on a different partition, seven remain:

Attribute	nodes 1 & 3 (work)	node 2 (broken)	Verdict
Fast Boot	Disable	Enable	plausible probability-shifter — the only live candidate
Legacy Boot Options	Disable	Enable	coincidence — the setting is INERT, see below
Microsoft / Windows / MS Option ROM UEFI CA 2023	Enable	Disable	coincidence (sub-page db size at most)
TPM Activation Policy	F1 to Boot	Allow user to reject	coincidence
Recover OS after Boot Failure	Disable	Enable	coincidence (but a policy problem in its own right)

After Power Loss is eliminated by the third node — node 3 works and shares node 2's Power Off; node 1 is the odd one out. It was never mechanistically credible (PCH/ME power policy, applied before firmware executes). It remains a §1 checklist violation on two nodes now.

Legacy Boot Options is affirmatively inert, which a naive diff gets wrong. Three attributes are identical on all three nodes and settle it: Configure Legacy Support and Secure Boot = "Legacy Support Disable and Secure Boot Enable", Configure Option ROM Launch Policy = "All UEFI", UEFI Boot Options = Enable. Legacy Boot Options is only the boot-order checkbox; the master switch that actually instantiates a CSM has legacy support disabled on node 2 too. No CSM is built, no legacy option ROM is shadowed. The second-strongest candidate has no boot-time allocation footprint at all. Secure Boot is likewise not a differential — all three log Secure boot enabled and load the same HP DB cert.

Fast Boot is the one credible mechanism, and for a different reason than the hypothesis this document previously recorded and killed. HP documents it verbatim: "reduces boot up time by bypassing boot to USB, CD-ROM, and PXE. This skips some preboot initialization steps." Skipped preboot init ⇒ fewer boot-services allocations before the MAT is installed ⇒ a different heap top ⇒ the MAT lands at a different address. That is exactly the perturbation that flipped the near-identical Dell case in LP #2039382, where the reporter's "fix" was unplugging a USB mouse. (The old Fast-Boot-caches-MRC-training theory stays dead — byte-identical BIOS-e820 refuted it.)

Verdict: the hypothesis is not supported, and this diff cannot support it even in principle

1. No setting can be the cause. Node 2 booted good once and bad twice with settings constant, and the MAT address moves every boot on all three machines.
2. Fast Boot may shift the odds. That is the honest ceiling. There is currently zero evidence that it does.
3. A fatal confound: the 1=3 ≠ 2 partition is perfectly collinear with two hardware differences that have at least as strong a mechanism — node 2 is the only single-DIMM node and the only NVMe-booting node. Nodes 1 and 3 are both dual-DIMM and both SATA. Adding node 3 did not break the confound; it doubled it. A different boot device means a different initrd module set and size, hence a different EFI-stub allocation footprint — the very thing that decides whether the MAT page gets overwritten.

No model-specific documentation exists. HP publishes nothing mentioning the EFI Memory Attributes Table, MAT placement, or an NX/DEP option on this generation. The only memory-adjacent options (Option ROM Launch Policy, DMA Protection, Pre-boot DMA protection) are identical fleet-wide. No HP advisory matches. The R21 changelog never mentions memory, and these nodes run 02.26.00 dated 05/05/2026 — newer than anything HP has indexed publicly, so there is no BIOS update to chase.

The experiment, if it is ever worth running

Two statistics kill the obvious approach. Node 2's failure rate is known only to n = 3 (2 bad of 3); the 95% Clopper–Pearson interval on p(bad) is ≈ 0.09–0.99. Against a null that loose, even 8 clean boots after a change prove nothing. A baseline arm is mandatory, and: detecting elimination needs ~20 boots per arm; detecting a mere odds shift (0.67 → 0.33) needs ~50 per arm for 80% power. Do not design for an odds shift — design for elimination and report "inconclusive" otherwise.

Zero-touch first step, and the one actually worth doing: 20 scripted reboots of node 2 with nothing changed, logging MEMATTR= and the Memory: …K/…K available line per boot. That establishes the real p(bad) we lack, and tests the causal chain directly — is the outcome predicted by where the MAT landed? Present data hint yes: both failures at exactly 0xbeeb0018, all five successes elsewhere. If the bad outcome maps onto a narrow address range, the mechanism is settled without touching anything.

If more is wanted, swap hardware rather than BIOS settings — it crosses settings against memory topology in one move, needs no firmware write (writes are refused; a BIOS change means a physical F10 visit per arm), and is work §2 wants anyway: move node 2's single Samsung DIMM into node 3 and node 3's matched pair into node 2, then 20 boots each. Fault follows the DIMM ⇒ topology, settings exonerated. Fault stays on node 2 ⇒ node 2 implicated, and only then is Fast Boot worth testing. Fault disappears ⇒ single-DIMM topology. ~1 hour unattended.

None of this changes the action. The fix is already known, is not in dispute, and applies to all three nodes: kernel ≥ 6.13.

What NOT to do

• Do not buy RAM, move the DIMM, RMA the board, or run memtest expecting failures. The DIMM is a 16 GB 2Rx8 Samsung C/D-die, DDR4-2666, on HP's supported population (DIMM1 must always be installed). Coffee Lake supports 16 Gb x8 regardless. A density fault would yield 8 GiB, never 2.6.
• BIOS 02.27.00 (sp174287) helps only by accident, by shifting where the table lands. The full R21 changelog 02.10.01 → 02.27.00 contains zero memory/MRC/DIMM entries.
• Rebooting, disabling Fast Boot, clearing CMOS, unplugging USB are all the same lottery ticket: they change the firmware's boot-services allocation footprint and hence where MEMATTR lands. They may appear to "fix" it. They are not fixes.

Hypotheses killed, and why — so they are not re-run

• Fast Boot / stale MRC training data — killed as a mechanism. Intel MRC caches are guarded by an SPD-derived CRC plus a firmware-version tag; a DIMM swap is exactly what that guard catches. HP documents Fast Boot only as a POST-diagnostics shortcut, never as an MRC control.
• Memory remap / above-4G decoding — no such attribute exists among the 241 exposed by hp-bioscfg on this platform.
• Integrated graphics — Graphics Stolen Memory is exactly 64 MiB, below 4 GiB.
• EFI_MEMORY_SP / "soft reserved" memory — the strongest competing theory, excluded by measurement: /sys/firmware/memmap/10/type reads System RAM for 0x100000000-0x42f7fffff. Soft-reserved ranges become E820_TYPE_SOFT_RESERVED, print as Soft Reserved, and are never memblock_add()ed — which would have left present at ~0, not 3340288.
• SGX — ruled out at runtime: x86/cpu: SGX disabled or unsupported by BIOS.
• MTRR trim — MTRRs near-identical to node 1, no trim warning.
• A last_pfn cap — a misreading; the second value is max_low_pfn and is normal.
• The 2.6 GiB figure was never a power of two, which fits no addressing theory. It is now exactly explained: everything from 0xbeeb0018 upward.

1. Firmware / BIOS (per node, before OS install)

These are MACHINE-CHECKABLE — but NOT machine-enforceable. The hp-bioscfg driver exposes 241 BIOS attributes at /sys/class/firmware-attributes/hp-bioscfg/attributes/ (239 have a current_value; 215 returned a non-empty value — an earlier note here said "215 attributes", which was the non-empty subset, not the total). Reads work fine: node 1 and node 2 were diffed programmatically, which is how the drift in §0b was found at all. Nobody could have spotted After Power Loss=Power Off on node 2 by eye.

Writes are refused by the firmware — verified 2026-09-01, hp_bioscfg: Returned error 0x4, "Invalid command type". HP requires BIOS-admin authentication and neither credential is provisioned (Setup Password is_enabled=0, SPM not provisioned). Setting these therefore means F10 on the box.

Follow-up worth doing: extend roles/node_health to ASSERT this checklist — that is achievable today with reads alone, and would have caught node 2's drift on its first health run. Converging it automatically additionally requires provisioning a BIOS Setup Password on every node, which is a real security decision (a stored credential that can rewrite firmware) and is the operator's call, not a default.

• Virtualization enabled — VT-x and VT-d. Required for KubeVirt (R-PLAT-03); verify after boot with /dev/kvm present and grep -cE 'vmx|svm' /proc/cpuinfo non-zero.
• AC power recovery = Power On. A homelab node must return after a power cut without a human pressing the button. (docs/02 calls out wake/boot behaviour explicitly.)
• Wake-on-LAN enabled on the onboard NIC (remote recovery when the box is off).
• Boot order — internal disk first; USB above it only while imaging. Disable network boot unless PXE is adopted.
• Secure Boot — record the setting. k3s itself is fine either way; note it so all three nodes match.
• Firmware version recorded in §0 and consistent across all three nodes.

1b. BIOS passwords and programmatic configuration — researched 2026-09-01

There is no default BIOS password, and no factory default exists to look up. HP business desktops ship with no Setup password and no Power-On password set; the is_enabled=0 we observe on both is the factory state, not drift. HP's own Maintenance & Service Guide for the 800 G5 describes both purely as things the owner configures in Computer Setup.

Owner recovery path, for the runbook: if a Setup password is ever set and forgotten, HP documents clearing it with the PSWD jumper on the system board (power off, open, remove jumper, boot once). Do NOT enable "stringent security" — HP documents that it removes the physical bypass entirely, turning a five-minute jumper fix into an HP service case requiring a signed, per-serial unlock. The permissive default is the right setting for a homelab.

CORRECTION — error 0x4 is NOT an authorisation failure

I recorded that the firmware refused our write because BIOS-admin authentication was missing. That was wrong, and the kernel driver misled me. hp-bioscfg passes the return value of HP's WMI SetBIOSSetting method through hp_wmi_error_and_message() — which is the error table for a different interface (the "SECU" commands under HP_WMI_BIOS_GUID). The two methods have unrelated return-code spaces. Per HP's Client Management Interface white paper, SetBIOSSetting returns:

Code	Meaning
0	Success
1	Not Supported
4	Failed (generic)
6	Access Denied

So the firmware said a generic "Failed". An authorisation problem would have returned 6, and the driver has a separate BIOS_ADMIN_NOT_SET = 0x38 → -EPERM for the no-password case — neither of which we saw. The string "Invalid command type" printed in our logs is the driver looking 4 up in the wrong table. This is a genuine upstream bug worth reporting to platform-driver-x86.

Most likely actual cause (inferred, testable): with an empty password the driver emits an untagged empty UTF-16 string, whereas every HP-documented caller passes the encoding tag even when blank (Password = "<utf-16/>"). The driver only prepends that prefix for a non-empty string. So setting a Setup password may well fix writes — but not because 0x4 means "unauthorised"; it would work by flipping the driver onto the tagged code path HP's own tools use. Corroborating smell: this firmware already makes the driver log Prerequisites size value exceeded the maximum number of elements supported or data may be malformed at boot.

hp-bioscfg cannot set a password — verified from source. Both current_password and new_password funnel into store_password_instance(), which only strscpys into driver RAM; nothing ever transmits new_password to firmware. It is write-only into a buffer that is never read.

Recommendation

1. Land the read-only drift check now — encode this §1 checklist as expected values, diff current_value on every node in roles/node_health, fail on mismatch. That is the whole R-ENV win, at zero risk and with no new credential, and it is available today. Remediate by hand at F10.
2. Do not provision a Setup password "to fix the auth error" — there is no auth error. Provision one only as a deliberate experiment on node 3 (not yet built): set it at F10, write it to current_password, retry one benign attribute. Return 0 confirms the <utf-16/> theory; 6 would mean a password mismatch; another 4 means the driver is incompatible with R21 and the fallback is hp-repsetup.
3. Fallback if that fails: HP's own Linux tool hp-repsetup (HP Flash and Replicated Setup Utilities, v3.26) can both dump/apply settings and set the Setup password from Linux — but it needs the out-of-tree hpuefi.ko, which requires Secure Boot disabled or the module self-signed. Secure Boot is currently enabled on these nodes, so this costs either a signing setup or a security downgrade.
4. Skip HP Sure Admin / SPM and BCU. Sure Admin's key-based model is genuinely better in principle — the private key never leaves the workstation, each change is individually signed, with anti-replay — but provisioning and every signature require Windows-only tooling. For three machines whose firmware settings change roughly never, the operational cost far exceeds the risk reduction. BCU is Windows/WinPE-only.
5. Security trade-off if you do provision a password: it is a shared credential granting full pre-OS control of all three nodes (disable Secure Boot, re-order boot, re-enable ports) — functionally equivalent to unsupervised physical access. Exposure is bounded in that using it via hp-bioscfg needs root on the node already (sysfs is --w-------), so the marginal loss is persistence and pre-boot control rather than initial compromise. Note hp-repsetup -p takes the password in cleartext on the command line — it would land in process listings and shell history unless wrapped. Store it in the Ansible vault and offline.

2. Disk layout — OPEN DECISION, blocks the build

docs/02 requires the OS-vs-Longhorn device split to be documented before prod build. Dev went further and added a third device for etcd after HDD contention starved etcd WAL fsync (docs/plans/ssd-etcd-isolation.md).

Node 1 as-found is a single 477 GB SATA SSD carrying everything:

sda  477G  C400-MTFDDAC512M (SSD, ~2011-era Micron/Crucial)
├─sda1 976M  /boot/efi
├─sda2  30G  /
├─sda3  12G  /var
├─sda4 977M  swap
└─sda5 433G  /srv          <- the only large free space

Consequences to settle before imaging nodes 2 and 3:

• Drive health MEASURED 2026-09-01 (smartctl -a /dev/sda, via the baseline package floor — see §5). Raw attributes, so the numbers are auditable:

  | | |
  |---|---|
  | Model | Crucial/Micron RealSSD m4/C400/P400 (`C400-MTFDDAC512MAM`, fw `070H`) |
  | SMART self-assessment | **PASSED** — no attribute in `WHEN_FAILED` |
  | Power-on hours | 6,814 (~284 days) · 147 power cycles |
  | **Rated life used** | **31%** (`202`), i.e. 69% remaining (`173` VALUE 069) |
  | **Grown failing blocks** | **15** (`170`), reallocation events **15** (`196`) |
  | **Erase failures** | **187** (`172`) |
  | **Unexpected power losses** | **32** (`174`) |
  | Pending / offline-uncorrectable / reported-uncorrectable | **0 / 0 / 0** (`197`/`198`/`187`) |
  | UDMA CRC errors | 0 (`199`) — cabling is clean |
  
  **Read attribute `5` carefully.** Its raw value is `61440`, which is NOT a bad-sector
  count: `61440 = 15 x 4096`, and both `170` and `196` independently read **15**. Its
  normalised VALUE is 100 against a THRESH of 10. So the drive has **15 grown bad blocks**,
  not sixty-one thousand bad sectors. The first `node_health` run FAILED on that raw value;
  the check now judges on normalised VALUE/THRESH, `WHEN_FAILED`, and the vendor-independent
  uncorrectable counters instead.
  
  **Verdict: usable, but not for production state.** Nothing says imminent failure — no
  pending or uncorrectable sectors, SMART self-assessment passes. But this is a ~2011
  consumer MLC drive that has already consumed **31% of its rated life**, grown **15** bad
  blocks, logged **187** erase failures, and taken **32** unclean power losses **with no
  power-loss protection**, in a single failure domain. etcd is the worst possible tenant for
  it: etcd fsyncs constantly, and an unclean power loss on a drive without PLP is exactly how
  a member corrupts — this drive has already logged 32 of them.
  (Non-ECC RAM is a separate, **accepted** risk — operator decision 2026-09-01, see
  `DECISIONS-LOG.md`. It is not part of this verdict.)
  

• Decide the layout.- [ ] Decide the layout. roles/node_baseline expects block devices (node_baseline_longhorn_device, node_baseline_etcd_device) and makes a filesystem on them. Its defaults /dev/vdb and /dev/vdc are virtio names that do not exist on bare metal — prod must override them in group_vars. On a single-disk node there is no second device at all, so one of: - Add a second drive (M.2 NVMe if the chassis has a free slot; verify physically — only a SATA controller is populated today). Cleanest: matches dev's isolation, gives etcd its own spindle. - Use /dev/sda5 (the 433 GB /srv partition) as the Longhorn device, etcd stays on /. Buildable today, zero spend, but re-creates the shared-spindle contention dev was burned by. - Repartition into dedicated OS / etcd / Longhorn partitions. Better isolation, still one physical failure domain.

• All three nodes get the identical layout. Longhorn replica placement assumes symmetry.

• Record the chosen device paths here and set them in infra/ansible/inventory/group_vars/k3s_prod/vars.yml (they are deliberately /dev/BLOCKED-pending-disk-decision-… placeholders today — do not guess). A full node-baseline run against a node still carrying those placeholders now stops on an explicit assert naming this section, instead of failing obscurely at mkfs time.

• The SMART-vs-smartmontools circular dependency is broken (2026-08-31). roles/node_baseline is tagged packages / system / disks, so the package floor can land without the disk tasks this decision blocks — see §5's drive-health box for the exact command.

3. OS install (per node)

• Debian 13 (trixie), matching dev exactly — same kernel series, same package baseline.
• Hostname k3s-prod-N.
• Partition per the §2 decision.
• No cloud-init needed. Dev's first-boot work was deliberately moved into roles/node_baseline when provisioning became API-only (infra/cloud-init/ is a README now), so the same role covers bare metal. Nothing to port.

4. Network (per node)

• Static IP on the prod LAN, recorded in §0. Node 1 is 192.168.2.10/24, gateway 192.168.2.1.

• Prod address plan — DECIDED (operator, 2026-08-31).

  | Role | Address | Owned by |
  |---|---|---|
  | `k3s-prod-1` / `-2` / `-3` | `192.168.2.10` / `.11` / `.12` | Ansible inventory |
  | **kube-vip control-plane VIP** | `192.168.2.9` | Ansible (`group_vars/k3s_prod`) |
  | **Ingress Gateway VIP** (`GATEWAY_VIP`) | `192.168.2.20` | Flux (`clusters/prod`) |
  | **Cilium L2 announcement pool** | `192.168.2.20` – `.30` | Flux (`platform-config/cilium`) |
  
  Two deliberate properties, both mirroring dev:
  - The **control-plane VIP sits outside the LB pool** (`.9`, below the nodes), so kube-vip and
    Cilium LB-IPAM can never contend for the same address. Dev achieves this the other way
    round (`.49` control-plane, pool `.53-.60`).
  - **`GATEWAY_VIP` is the FIRST address of the pool.** Cilium LB-IPAM can only allocate from a
    defined pool block, so a Gateway VIP outside every pool would not be allocatable — the pool
    was widened from `.21-.30` to `.20-.30` for exactly this reason. Dev has the same shape
    (`GATEWAY_VIP` `.53` = first of `.53-.60`).
  

• Reserve all of 192.168.2.9 and .20-.30 outside any DHCP range on the prod LAN before the build, and confirm nothing else on the network already answers on them.

• Resolver: SECOND UPSTREAM IS AN OPEN DECISION — blocks node-baseline.yml --tags dns. Node 1 has a single IPv4 nameserver, 192.168.2.1, which is also the LAN gateway. A single upstream is a known SPOF that has already bitten this project — it broke containerd image pulls and CoreDNS forwarding on dev.

  The MECHANISM is now in the repo and needs no further work: the `dns`-tagged block in
  `roles/node_baseline` detects whether a node uses systemd-resolved (dev: writes
  `/etc/systemd/resolved.conf.d/99-k3s-dns.conf`, restarts resolved) or a directly-managed
  `/etc/resolv.conf` (prod's shape: writes the file, refusing if resolvconf/NetworkManager
  owns it), and configures the ordered upstream list either way. The earlier
  `fix/node-dns-resilient-upstream` branch was **dropped, not merged** — it wrote a netplan
  drop-in and ran `netplan apply`, and netplan is not installed on these Debian 13 trixie
  nodes, so it would have broken `node-baseline.yml` on every host.
  
  What is still MISSING is the VALUE. `group_vars/k3s_prod/vars.yml` sets
  `node_baseline_dns_servers` to `192.168.2.1` followed by the deliberately invalid
  `BLOCKED-pending-second-upstream-decision-see-PROD-PROVISIONING-md-4`, and the role's assert
  stops the play on it before writing anything. Choosing the second upstream is a **network
  decision, not a default the role may take**: a public resolver (`8.8.8.8`, `1.1.1.1`) would
  resolve reliably but would also bypass any local zone and any filtering the gateway applies.
  Decide between — and record the choice HERE, in the same change that edits the group_vars:
  - a second on-LAN resolver on `192.168.2.x`;
  - the dev-side PiHole `192.168.1.18`, **if** prod can actually route to it (unverified —
    prod sits on the workstation side of the pfSense boundary);
  - an explicit, written-down acceptance of a public resolver as fallback-only.
  
  Also decide whether node 1's current IPv6 nameservers (`2001:4860:4860::8888` / `::8844`)
  are kept: the direct-file write path replaces `/etc/resolv.conf` with exactly the listed
  servers, so keeping them means listing them explicitly.
  `node_baseline_dns_search` is `[]` (no search domain, node 1's behaviour today) until prod's
  local domain is decided.
  

• Confirm the prod LAN's relationship to the dev LAN (192.168.1.x) and to the pfSense NAT — prod on 192.168.2.x sits on the workstation side of the boundary dev lives behind.

5. Access (per node) — blocks all Ansible

• k3s user with the home_network SSH key. Working on node 1.
• Password-protected sudo, driven by Ansible become + a vaulted password. Prod does NOT use NOPASSWD sudo (operator decision, 2026-08-31). Dev nodes do; prod deliberately keeps the sudo password in place and supplies it to Ansible as an ansible-vault-encrypted var, exactly like the existing hypervisor and proxmox_hosts groups: inventory/group_vars/k3s_prod/ README.md how to (re)create the vault — committed vault.yml ansible_become_password: "..." — committed, ENCRYPTED The passphrase that decrypts it lives outside the repo at ~/.config/home-k3s/ansible-vault-pass (ansible.cfg :: vault_password_file), so plays still run unattended without a plaintext secret ever touching git. bash ansible-vault create inventory/group_vars/k3s_prod/vault.yml # ansible_become_password: ... Prod nodes must therefore set ansible_become: true in their group_vars and must not inherit any passwordless-sudo assumption from group_vars/all.yml.
• Drive health baseline (§2). Do not hand-install the tooling — package installation is the node_baseline role's job, never a manual apt-get on a node (operator ruling, 2026-08-31; same click-ops-never principle as the rest of the repo). smartmontools is part of node_baseline_packages, so it arrives with the baseline play — but a full baseline would hit the disk tasks §2 has not decided yet. Run the packages-only baseline instead (the disks-tagged tasks, including the BLOCKED-device assert, are not selected at all, so the placeholder device paths are never even templated): bash cd infra/ansible ansible-playbook playbooks/node-baseline.yml \ -e k3s_hosts=k3s_prod --tags packages --limit k3s-prod-1 (Needs group_vars/k3s_prod/vault.yml to exist first — the become password above.) Reading the drive is then: bash sudo smartctl -a /dev/sda # Power_On_Hours, Percent_Lifetime_Remaining, reallocated sectors Record the result in §2 and close the layout decision in the same change that replaces the two node_baseline_*_device placeholders.

6. Ansible baseline & cluster join

Reuses the dev roles unchanged — that reuse is R-ENV-02. Only inventory and group_vars differ, plus a target-group override on the command line.

How prod is targeted (done, 2026-08-31)

Every node-host play used to hardcode the literal dev groups k3s_servers / k3s_primary / k3s_secondary, so nothing here could select prod at all. Two knobs now close that, deliberately kept separate because Ansible resolves them at different times:

Layer	Knob	Set via
Which hosts a play runs on	k3s_hosts, k3s_primary_hosts, k3s_secondary_hosts (each defaults to the dev group)	-e extra vars only — a play's hosts: is templated before any host exists, so group_vars is not readable there
Which group a role means by "my primary" / "my servers"	k3s_primary_group, k3s_servers_group, cluster_kubeconfig_name	group_vars — dev in all.yml, prod in k3s_prod/vars.yml; no per-run flag

So roles/k3s_server finds the prod --cluster-init founder, builds the prod join target and tls-san list, and roles/cilium fetches the prod kubeconfig, with no role fork. Running with no extra vars is byte-for-byte the dev behaviour it always had (verified by a before/after --list-hosts diff on every playbook). Full detail: infra/ansible/README.md → Targeting prod.

• Add a k3s_prod inventory group (k3s_prod_primary / k3s_prod_secondary). Prod is reached directly on the LAN — no NAT port-forward hop, unlike dev's 192.168.2.102:225x mapping. (Nodes 2/3 stay commented out until they are physically on the bench.)
• inventory/group_vars/k3s_prod/vars.yml: kube_vip_address (192.168.2.9), cluster_controller_api_server, k3s_api_host, the group-name overrides above — and the §2 device overrides for node_baseline_longhorn_device / node_baseline_etcd_device, which are still BLOCKED placeholders.
• inventory/group_vars/k3s_prod/vault.yml — the vaulted ansible_become_password (§5). Until it exists no prod play can escalate, and --check against prod cannot work either.
• Run the packages-only baseline first, to unblock the §2 drive-health read: bash ansible-playbook playbooks/node-baseline.yml -e k3s_hosts=k3s_prod --tags packages
• Run the full playbooks/node-baseline.yml -e k3s_hosts=k3s_prod → packages, kernel modules, sysctls, iscsid, data-disk filesystems + mounts. Blocked until §2 is decided: it asserts on the placeholder device paths and stops. (qemu-guest-agent is a no-op on bare metal — the role already only starts it when the virtio channel exists, so it degrades cleanly.)
• Run playbooks/k3s.yml -e k3s_primary_hosts=k3s_prod_primary -e k3s_secondary_hosts=k3s_prod_secondary → HA embedded etcd, flannel/kube-proxy/Traefik/servicelb disabled. Only once all three nodes are present — see §8.
• Run playbooks/kube-vip.yml -e k3s_hosts=k3s_prod → control-plane VIP (192.168.2.9) on the prod LAN.
• Run playbooks/cilium.yml -e k3s_hosts=k3s_prod → CNI at bootstrap; Flux's HelmRelease adopts it afterwards. The bootstrap values and the HelmRelease must stay in parity (kubeProxyReplacement, k8sServiceHost/Port) or the two layers fight over CNI config (docs/02). Note the prod kubeconfig is fetched to .cache/prod.kubeconfig, never over the dev one the dev container exports as $KUBECONFIG.
• Run playbooks/verify.yml -e k3s_hosts=k3s_prod.
• playbooks/flux-bootstrap.yml -e k3s_hosts=k3s_prod retargets but is not yet correct: roles/flux_bootstrap shells out to bootstrap/flux/bootstrap.sh, which bootstraps --path=clusters/dev. Prod needs --path=clusters/prod — a bootstrap/ change, not a target-group change. Tracked with the other repo blockers in §7.
• Decide whether prod runs a VPN egress gateway node (dev uses k3s-dev-3, ADR-0015). playbooks/vpn.egress.gateway.yml takes -e vpn_egress_gateway_hosts=<group>, but there is deliberately no prod egress group in the inventory yet, and it would need its own vaulted PIA credentials — the existing vault is scoped to the dev group.

7. Repo blockers — prod cannot be reconciled until these land

clusters/prod is design-only today and would build wrong. R-ENV-02 promises dev and prod differ only by cluster-vars values; in practice dev LAN addresses are hardcoded into base manifests:

Hardcoded value	Where	Prod needs
k8sServiceHost: 192.168.1.50	platform/cilium/helmrelease.yaml:50, mirrored in values.yaml:16	prod primary node IP
LB pool 192.168.1.53–.60	platform-config/cilium/l2-ip-pool.yaml:15	a prod-LAN pool
192.168.1.55 (crafty)	platform/crafty/service-l4.yaml	prod-LAN address
192.168.1.54 (UniFi VM)	apps/vms/unifi/50-service-l4.yaml	prod-LAN address
192.168.1.9:9000 (S3 backup)	platform/keycloak/postgres-cluster.yaml, apps/wave-0/{nextcloud,semaphore}-db.yaml	reachable prod backup target

• Tokenize each into a cluster-vars knob with a base default, then set the value in both overlays. Adding a knob before referencing ${KNOB} is the sanctioned mechanism (see the header comment in clusters/base/cluster-vars.yaml). platform, platform-config, the app waves, apps-vms and crafty all already carry postBuild.substituteFrom: cluster-vars, so the seam exists.
• clusters/prod must set GATEWAY_VIP. It currently doesn't, so prod would inherit the base default 10.73.0.240 — an address from the retired libvirt network. The base file's own comment flags this as owed "when hardware is built."
• Dev overlay sets every new knob to today's exact value so rendered dev output is byte-identical and the live cluster sees zero drift. Verify with make -C ci render-golden.
• clusters/prod is NOT bootstrappable as-is — three gaps, found 2026-09-01 while landing the dependsOn fix. Only the first is now closed: - [x] Root Kustomization — clusters/prod/sync.yaml authored, mirroring dev. This became load-bearing, not cosmetic: clusters/base/platform.yaml now carries dependsOn: [flux-system], so without a root object on prod, platform would block forever on a dependency that does not exist and nothing downstream would reconcile. - [x] SOPS decryption — DONE. Operator decision 2026-09-01: prod uses the SAME age key as dev. Eight decryption: {provider: sops, secretRef: sops-age} patches mirror dev exactly. The sops-age Secret is still created OUT OF BAND on the prod cluster (bootstrap/sops/install-age-key.sh) — the overlay references it by name only. - [~] GitRepository source — BRANCH settled, URL still blocked. Operator decision 2026-09-01: prod tracks main, the same branch as dev, because dev is temporary and will be decommissioned once prod is stable. Recorded consequence: once prod is live, every merge to main reconciles BOTH clusters — no promotion step, no soak window. The URL is patched in but cannot work on a cold prod cluster, for two independent reasons found 2026-09-01: 1. Self-hosting circularity — Gitea runs on the DEV cluster, the one slated for decommission. Gitea must move to prod (or off-cluster) BEFORE dev is retired, or prod loses its source of truth. This is the decommission plan's first task, not its last. 2. Split-horizon sends it to the wrong place — coredns-custom answers the entire home.keithjackson.dev zone with ${GATEWAY_VIP}, which on prod is 192.168.2.20: prod's OWN gateway, where no Gitea listens. Prod's Flux would resolve gitea.home.keithjackson.dev to itself and never reach a repository. Bring-up needs a TEMPORARY source (bootstrap host-Gitea, or an off-cluster mirror) and a cutover once Gitea runs on prod — the same sequence docs/05 describes for dev's own Phase-6 cutover.
• Confirm prod's backup target: dev's S3 (versitygw on the Proxmox host, 192.168.1.9) is on the dev side of the network. Off-cluster backup is DR-critical (R-STATE-03).

8. Build sequence (operator decision, 2026-08-31: wait for all three nodes)

Node 1 is baselined now; the cluster is not initialized until nodes 2 and 3 are on the bench. This keeps prod spec-conformant (3-node HA embedded etcd) from its first boot, avoids a single-server-etcd window, and avoids a later member-add dance.

1. Per-node §1–§5 on each of the three boxes.
2. §7 repo work lands on main with the gate green.
3. node-baseline → k3s (all three) → kube-vip → cilium.
4. flux bootstrap ... --path=clusters/prod.
5. Conformance against prod (§9).

9. Exit criteria (Phase 7)

• Prod runs the same config as dev via the prod overlay, no base edits (R-ENV-02).
• Node destroy/rebuild from IaC + Ansible without data loss (R-ENV-01, R-STATE-01).
• Full automated prod DR drill (R-STATE-03) — definition-of-done.md requires this for prod specifically.
• Monitoring and alerts live on prod.
• The conformance suite passes green against the prod cluster, not just dev (R-TEST-03).