Cluster storage
Experimental: validate storage, backup, and recovery behavior for every workload before production use.
FleetClusterJoin accepts storage intent during cluster creation. After a cluster is Ready, the authenticated storage-configuration API supports NFS backends only. Changing an applied NFS server or cluster export path is not supported; migrate workloads instead.
| Backend | Intended use | Constraint |
|---|---|---|
local_path |
K3s local storage | Default local-only option |
nfs_external |
Shared external NFS | Requires an operator-provided NFS server and per-cluster path |
nfs_local |
Single-node local RWX | Restricted to a single-node cluster |
longhorn |
HA cluster storage at creation | Restricted to the supported HA creation path |
Single-node local RWX (nfs_local)
Section titled “Single-node local RWX (nfs_local)”Use this when a single-node cluster needs ReadWriteMany without an external NAS. UMKIM installs nfs-server on the node, exports a local path (default /srv/fleet-nfs), and deploys StorageClass nfs-client.
- At create: on Create cluster (single-node), enable Local RWX.
- After Ready: cluster detail → Operations → Enable local RWX, or:
umkim cluster storage enable-local CLUSTER [--dir /path] [--wait 10m]umkim cluster storage status CLUSTERStorage configure is mutually exclusive with node lifecycle and KubeVirt platform jobs and is recorded in operation history as configureStorage. The NFS StorageClass often becomes the cluster default; set storageClassName on PVCs when you need a different class.
nfs_local is a convenience backend for single-node evaluation, not a substitute for managed shared storage.
NFS safety
Section titled “NFS safety”UMKIM does not secure or operate an external NFS server. For nfs_external, use a dedicated export and unique directory for each cluster, restrict clients, keep root squashing enabled unless a documented exception is required, and verify mount and write behavior.
Longhorn is validated only for the HA creation path. A successful validation probe is not a durability, availability, or backup guarantee. Check the resulting StorageClass, provisioner rollout, and a representative PVC using verification.