Files
felhom.eu/REPORT-campaign8.md
T
admin 14b0939060 docs: CAMPAIGN 8 — adversarial backup & restore campaign report
Unattended 10h run against demo-felhom, demo-hp and ep0. No production code
changed; findings recorded and ranked, not fixed inline.

8 findings, 2 HIGH — both in the system's ability to report that a backup did
NOT happen:
- F-CRIT-1: an app failing to restart after a quiesce never alarms (invariant
  I1 in main.go:1213 is false for the failed-restart path)
- F-CRIT-2: a failed offsite backup leaves a phantom snapshot that resets the
  tier's freshness clock (NewestArchiveTime has no completeness check)

Retires several never-validated items, including R-87 (first restic restore
round-trip, byte-verified), the full R-88 backoff ladder, age_state=absent,
and the crash-recovery unquiesce under a real SIGKILL.

peti-felhom untouched; ep0 rollback copy intact; fleet healthy at end.
2026-07-28 01:59:59 +02:00

3.8 KiB
Raw Blame History

REPORT — CAMPAIGN 8: the backup & restore subsystem (2026-07-27/28)

Adversarial, destructive, unattended run against demo-felhom, demo-hp and ep0. Full report: documentation/audits/CAMPAIGN-8-backup-restore-2026-07-27.md. Evidence: DooPlex:~/campaign8/evidence/ (103 files, 35 MB, written continuously by 11 collectors).

No production code was changed. Findings are recorded and ranked, never fixed inline, per the campaign's own rules.

Scope safety

peti-felhom, its namespace and u629488-sub2 were never touched. Phase 0 established with five documented probes that peti has no data at all in felhom-offsite, which is what made the operator-approved 100% datastore-fill safe. The 13 GB rollback copy /srv/pbs-felhom on ep0 is intact.

Findings

# Finding Severity Class
F-CRIT-1 An app that fails to restart after a quiesce never alarms, on any channel HIGH DEFECT
F-CRIT-2 A failed offsite backup leaves a phantom snapshot that resets tier freshness (up to 7 days silent on real cadences) HIGH DEFECT
F-A1 A restore-test in progress makes a healthy backup report as FAILED, arms the breaker, pages the operator MEDIUM DEFECT (behaviour) / ARTIFACT (frequency)
F-HUB The hub dropped an event under concurrent load (SQLITE_BUSY), no retry, cause unnamed MEDIUM DEFECT
F-LEAK A leaked restore-test scratch guest is never reclaimed; the 10-slot VMID band shrinks silently MEDIUM DEFECT
F-DIAG Four distinct offsite failure causes collapse into two operator-visible strings LOWMED DEFECT
F-OBS deadapp-check leaves no positive observable on a default (info-level) box LOW DEFECT
F-OPS A manual pct restore inherits the source guest's binds (live data drive + another guest's credentials) LOW Operational

Both HIGH findings are in the same place: the system's ability to tell you a backup did not happen. Both cite the code and the comment that asserts the property the code does not provide.

What is now proven that was not before

R-88 breaker arming and its full ladder (15m/30m/1h/2h/4h/4h-cap) · per-tier isolation under a real one-tier-fails case · whole_guest_backup_failed end-to-end with correct tier attribution · R-97c operator-only routing verified against the hub DB (zero customer rows with status='sent') · whole_guest_backup_recovered + the R-68 pairing gate firing live · age_state=absent · R-97b's suppression half · the crash-recovery unquiesce by an actual SIGKILL (1 s) · R-87 — the first restic restore round-trip ever performed, byte-verified (6/7 sha256 identical, the 7th explained) · R-82 one-quiesce-two-tiers · single-flight on two independent paths.

Restore round-trips

restic (R-87) · local vzdump → fresh CT · PBS offsite → fresh CT · corrupted snapshot → fails cleanly. mount_parity exact on both whole-guest tiers, unprivileged: 1 preserved.

Fleet state

Healthy. Nothing left broken. All four compression knobs reverted and verified; every fault unwound; no leaked scratch guests, nft rules, ballast files or clock skew; ep0 datastore clean with zero .bad chunks. demo-felhom 15/15 containers healthy, demo-hp 8/8.

Not tested (with reasons)

Fault 4 (restic transport — four injection approaches defeated by guest-bridged networking; the most valuable follow-up, because F-CRIT-2 raises the same question for restic), faults 11/12 (reboots — reasoned skip after F9/F10 covered hard-kill crash safety), fault 18, fault 13's GC leg, and the agent's own DR bring-up path. Faults 6 and 8 were inconclusive for documented reasons.

Note on repo conventions

This run touched no hub/, scripts/ or website/ code, so none of the per-area CHANGELOGs has an entry — there is nothing shipped to log. The deliverable is the audit document plus this report.