4cb5e7a8d4cd76287c34d5912f4344f8c1fffa79
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Commits
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0b3db6e778 |
fix(node_health): SMART verdict was wrong by 4096x — judge on portable signals
The first real SMART run FAILED k3s-prod-1's drive on reallocated=61440. That verdict
was WRONG, and the failure mode is instructive: the check trusted a VENDOR-DEFINED raw
value as if it were an ATA-standard sector count.
Micron TN-FD-20 ("SMART Attributes for the C400 SSD") names attribute 5 "Reallocated
BLOCK Count" and defines its raw as grown-bad-blocks x Block_Sector_Count, where
Block_Sector_Count is 256 x 16 = 4096 for the 128Gb-NAND parts (256GB/512GB). This is
the 512GB C400-MTFDDAC512MAM: 61440 / 4096 = 15. Triply corroborated on the drive itself
— attr 170 Grown_Failing_Block_Ct = 15, attr 196 Reallocated_Event_Count = 15, attr 5
normalised value 100 against thresh 10, and `when_failed` empty on every attribute.
FIFTEEN grown bad blocks, not sixty-one thousand bad sectors.
smartctl(8) states it outright: since ATA/ATAPI-4 rev 4 the meaning of raw Attribute
fields is "entirely vendor-specific". So a raw value can never be a portable verdict.
FAIL now comes only from signals that mean the same thing on every drive: the drive's own
smart_status.passed; NORMALISED value vs the MANUFACTURER's own threshold via smartctl's
when_failed ("now"/"past"/""), split Pre-fail -> FAIL and Old_age-or-past -> WARN; the
ATA-standard counters 197/198/187 (199 CRC is WARN-only — it is link, not media); and for
NVMe critical_warning / media_errors / percentage_used. Wear reads from the NORMALISED
lifetime indicator (202/231/233, or NVMe percentage_used) — a percentage by definition.
Vendor raw counts are still collected and PRINTED WITH THEIR NUMBERS, and may raise a
WARN, but can never drive a FAIL. Attribute 5's raw is now shown beside the normalised
reading that contradicts it, labelled vendor-encoded, with a mechanically-derived
"(= 15 x 4096)". Endurance attributes are matched by THE NAME smartctl's drivedb resolved
for that model, not by bare ID — drivedb is the portability layer; on an unrecognised
drive the name is Unknown_Attribute, nothing matches, and the field stays null with no
claim made. The STORAGE section now prints 170/172/173/174/189/206, whose previous
omission is exactly what let the misread stand unchallenged.
Also documented from TN-FD-20: on this family attr 197 "will always be 0, as reallocation
will be done on-the-fly" — so pending=0 is NOT evidence of health here. The role reports
the number and infers nothing from it.
Branches real hardware cannot exercise were verified with a harness rendering the actual
role expressions against synthetic smartctl payloads: virtio/no-stdout -> SKIP; NVMe
healthy -> PASS; NVMe degraded -> FAIL; a genuinely dying ATA drive (attr 5 normalised 8
<= thresh 10, pending 48) -> FAIL driven by the threshold trip and standard counters, not
the raw; unknown-vendor attrs -> PASS with the unnamed counter ignored; failed-in-the-past
-> WARN.
NEW VERDICTS. k3s-prod-1: 0 FAIL / 4 WARN / 12 PASS / 1 SKIP — SMART is a WARN naming the
real findings (31% of rated life consumed, 15 grown bad blocks, 187 erase failures, 32
unexpected power losses on a drive with no power-loss protection). k3s-dev-1: unchanged,
all three virtio disks still SKIP with their stated reason.
BREAKING (JSON artifact): the fact `reallocated_sectors` is renamed and gone — that name
asserted a unit ATA does not guarantee. Replaced by realloc_attr (the whole attribute,
normalised + raw), realloc_events, and grown_bad_blocks. Nothing in the repo reads it.
Serves: R-ENV-03, R-OBS-04.
Co-Authored-By: Claude Opus 5 (1M context) <[email protected]>
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c1f24e4a6d |
fix(dns): resilient node resolvers — mechanism-detecting, per-environment (R-DNS-01/03)
Re-authors the fix stranded on origin/fix/node-dns-resilient-upstream (
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9f59c36000 |
feat(ansible): node_health role — read-only hardware health for prod + dev nodes
Operator ask: implement the roles needed to check prod node hardware health, and run them to find out our state. This is that role; the run's findings are below. roles/node_health is a read-only sibling to cluster_verify (cluster health vs hardware health), styled after node_baseline. One unprivileged collector script does the work in a single SSH round trip — reading /sys/class/dmi, thermal + hwmon, EDAC, cpufreq + thermal_throttle, /proc/pressure, /sys/block incl. SCSI ioerr/iotmo counters, lsblk, lscpu, mounts + statvfs, per-NIC stats, resolv.conf. THE DESIGN POINT: an unreadable field is emitted as null WITH A RECORDED REASON, never as zero. The summary ends with a "NOT READ (and why) — these are UNKNOWNS, not passes" section. A fake zero on a reallocated-sector count is exactly the kind of false green this project refuses. 22 checks report PASS/WARN/FAIL/SKIP/INFO; every SKIP says why. Report-only by default; thresholds live in defaults/main.yml. Portable across bare metal AND VMs — validated against k3s-prod-1 (bare metal, no root) and k3s-dev-1 (VM, root). VM-absent things (SMART on virtio, coretemp, EDAC) skip cleanly, and iSCSI/Longhorn volumes are split out of the physical-disk set so a live replica is never mistaken for a spare device. playbooks/node-health.yml takes its target group as a variable (-e node_health_hosts= k3s_prod), deliberately unlike the other playbooks that hardcode k3s_servers — see the group-name gap already flagged in hosts.ini. Two become facts found the hard way and documented in the role: a group_vars `ansible_become: true` OUTRANKS `become: false` as a play/task keyword, so unprivileged tasks must override the variable; and `failed_when: false` does NOT catch "Missing sudo password" — only `ignore_errors` does. FIRST RUN, k3s-prod-1, 2026-08-31: 0 FAIL · 3 WARN · 12 PASS · 3 SKIP · 4 INFO. Box is healthy, cool and unstressed: i7-9700T 8C/8T, VT-x + /dev/kvm (KubeVirt OK), zero throttle events, hottest sensor 33C, PSI 0.00 across the board, 31.1 GiB RAM, eno1 up at 1000 Mb/s, BIOS R21 02.26.00, no reboot pending. DRIVE HEALTH IS STILL UNKNOWN — the headline. SMART did not run, blocked TWICE over: no vaulted ansible_become_password for prod, AND smartmontools is not on the node at all (node_baseline has never run there). Power-on hours, wear, reallocated/pending sectors and drive temperature all remain unmeasured on a ~2011 consumer SSD. WARNs: kernel ioerr_cnt=6 on sda (read cautiously — four freshly attached iSCSI disks on dev each showed a flat 7, suggesting a fixed per-device discovery cost, not media trouble; attribution needs dmesg/root); 0.95 GiB swap still active (node_baseline does the swapoff); one IPv4 resolver only (the other two upstreams are IPv6 Google), which refines rather than resolves the DNS-SPOF finding. ESCALATION — ECC status is UNKNOWABLE on this hardware: /sys/devices/system/edac/mc exists but no controller is bound. Non-ECC consumer RAM. Silent memory corruption on a prod node would be undetectable. Recorded as a SKIP with reason, not a pass. Serves: R-ENV-01, R-ENV-03, R-OBS-04. Task: T-7.1. Co-Authored-By: Claude Opus 5 (1M context) <[email protected]> |