The k3s VM disks are HDD-backed, so a full Longhorn replica rebuild's
sequential I/O can saturate the spindle and starve etcd's WAL fsync,
crash-looping etcd and flapping the kube-vip VIP (observed during a
rolling node resize). Cap rebuilds to one replica per node at a time so a
node bounce or replica replenishment can never storm the disks.
Set via HelmRelease defaultSettings.concurrentReplicaRebuildPerNodeLimit
(GitOps-managed, permanent). replica-replenishment-wait-interval stays at
the Longhorn default of 600s. Reference values.yaml kept in sync.
Co-Authored-By: Claude Opus 4.8 <[email protected]>
The 39Gi/node Longhorn data disks at 1:1 over-provisioning can't fit the media stack
(plex 20Gi replica failed: 'insufficient storage'). Volumes are thin-provisioned config-only,
so 200% lets the full catalog fit without a disk resize; physical fill risk is low. Also
right-sized plex config (20Gi was excessive for metadata). Prod-grade path: grow the data
disks (WS-STORAGE follow-up).