# gce.instance_reset (layer 2, large impact, reversible)

When: a pet VM (selfheal-obs, selfheal-harness, selfheal-db-replica) is hung: no SSH, no metrics, docker not responding, while the instance status is RUNNING. Do not reset selfheal-db-primary on a suspicion; a primary outage is a layer-3 decision (db-primary-down.md).

Procedure (harness action gce.instance_reset, target {instance: selfheal-db-replica}): `gcloud compute instances reset`; the startup script re-runs vm/<role>/apply.sh and services come back in 2 to 4 minutes. Undo: none; the disk is kept.