Skip to content

staging host disk pressure (95%) blocks all provisioning — should the pool autoscale or self-clean? #47

Description

@drewstone

What happened

During a ~70-sandbox benchmark run on 2026-07-05 (~23:00 UTC), staging provisioning collapsed mid-run:

Provision failed — (container) — Provision failed during container phase:
No registered hosts below pressure guard: staging-host-agent-01(disk=95.08%>=95%)

Every subsequent create failed — the run's holdout phase got zero cells (the consuming loop correctly refused to emit a verdict; see tangle-network/supervisor-lab#19 for the run report). We moved the workload to the prod endpoint, which handled ~280 further sandboxes fine.

Questions / asks

  1. Why doesn't the staging pool autoscale? One registered host (staging-host-agent-01) appears to be the entire staging capacity. When it crosses the pressure guard, staging is hard-down for every consumer. Is a second host / autoscaling intentionally out of scope for staging, or just not wired yet?
  2. Is there disk reclamation on the host? Our workloads create sandboxes that pip install ortools (~50 MB each) into per-box venvs and are deleted afterwards. If image layers / overlay dirs / volumes from deleted sandboxes aren't garbage-collected, any sustained benchmark fills the host — 95% may be mostly reclaimable.
  3. Failure UX is good, capacity headroom isn't: the pressure guard failing loud is the right behavior (it saved our experiment from silent corruption). But a single-host staging with no GC means every heavy consumer will hit this.

Context for sizing

That day's load from one benchmark project: ~160 sandboxes on staging (CAD + firmware-style OR workers, each ~1–10 min, opencode backend, pip installs in-box). If that's enough to fill the host, GC or a pressure-triggered scale-out would pay for itself immediately.

Metadata

Metadata

Assignees

No one assigned

    Labels

    No labels
    No labels

    Type

    No type

    Fields

    No fields configured for issues without a type.

    Projects

    No projects

    Milestone

    No milestone

    Relationships

    None yet

    Development

    No branches or pull requests

    Issue actions