Ruling 1 (2 weeks of weekly offsite backups): localPruneSpec's blanket PBS
refusal is now scoped — an ADDITIONAL tier with an explicit keep_last may
prune its PBS target. The refusal still applies in full to the PRIMARY tier,
because BackupTarget() defaults to felhom-pbs and KeepLast() defaults to 3, so
a box with neither key set would silently prune its offsite DR to 3 restore
points. An additional tier cannot have that accident (keep_last defaults to 0).
Ruling 3 (first backup runs as long as needed; nothing else starts until done):
- additional-tier wait bound 6h -> 12h (measured ~33 MB/min => ~5h for a first
full 10 GB snapshot; 12h gives margin but stays bounded so a hung task still
surfaces)
- ONE BACKUP AT A TIME PER GUEST across all tiers: POST /backup returns 409
when a DIFFERENT tier is in flight, naming the busy tier, with NO data object
so nothing is parseable as the caller's own job. Same tier still returns that
job (202, unchanged).
- snapshotted now counts as in-flight, not just running — after the snapshot the
vzdump is still uploading and holding the lock. The old check left a window
where a second POST started a real second vzdump. Latent bug, closed.
Full suite green (29 packages); red-proof observed and restored.
Found by live validation on demo-felhom, not by review.
The first real PBS-targeted backup ran past the runner's hard-coded 30-minute
WaitTask bound. The agent stopped waiting and recorded success=false WHILE THE
VZDUMP KEPT RUNNING (still running 72 min later, 2.4 GB uploaded). Consequences:
the tier stays permanently due, the next attempt collides with the guest lock
the live vzdump holds, and the hub sees a DR tier that never succeeds — R-82's
'applied and empty' fault re-created by a timeout.
Measured: ~33 MB/min over wg to Hetzner, so a first FULL ~10 GB snapshot
projects to ~5h.
- BackupTargetConfig.WaitTimeoutSeconds: per-tier bound. Primary 30m UNCHANGED
(a local vzdump hanging 30m IS a real fault); additional tier 6h, sized from
the measurement.
- backup.NewBackupRunnerWithWait: per-instance (per-tier) bound.
NewBackupRunner keeps its signature, so restore-test/selftest are untouched.
- localapi.BackupTier.WaitTimeout: the fire-and-forget context is sized from the
tier, not a fixed 2h. BOTH bounds had to move — a 6h runner bound under a 2h
outer context reproduces the same false failure four hours later.
Same direction as restore_test_pbs_restore_timeout_seconds: when in doubt wait
LONGER. A slow backup is a slow backup; a false timeout is a corrupt status
plus lock contention.
Red-proof observed and restored; full suite green.
Mechanism only. No box changes behaviour until a backup_targets entry is
added to its config (Slice D); an untouched config resolves to exactly one
tier and behaves byte-identically to v0.96.0.
- config: BackupTargetConfig + ExtraTargets + BackupTiers(); each tier carries
its OWN cadence and retention (keep-last=3 is three days on a daily tier and
three weeks on a weekly one). A missing cadence is REJECTED, not defaulted —
a weekly DR tier silently running daily would fill the 37.2 GB datastore.
main.go logs every rejection at ERROR.
- /backup/due?target= judges a tier against its OWN newest successful backup.
Without that filter a fresh local backup satisfies the weekly PBS cadence and
the DR tier never runs — today's bug, re-created in code.
- GET /backup/tiers advertises the tiers; a 404 is the controller's pre-R-82
capability probe (Slice B).
- Jobs keyed by (vmid,target): single-flight is per tier, which is what lets
the weekly night run both backups in ONE quiesce window. Job ids are unique
per tier by construction, not by clock luck.
- One runner per tier: the runner holds target+retention as immutable state,
so parameterising one runner would risk pairing tier A's target with tier B's
retention.
COMPATIBILITY (frozen): untargeted /backup/due, POST /backup and
/backup/status keep the primary tier and the pre-R-82 response BYTES —
Target is omitempty and stays empty. The primary's job-id format is unchanged.
NOT changed: the local tier; PBS is still never pruned by the per-run flag
(keep_last defaults to 0 = never prune — enabling DR pruning is irreversible
and needs an operator ruling).
Tests 748->768. Red-proof #1 observed and restored.
Phase 0: felhom.eu/documentation/audits/SPIKE-r82-phase0-2026-07-26.md
Claude Code