Concepts
Five mental models behind storage on Kubernetes clusters in Vantage.
Storage types
Vantage exposes three storage primitives on Kubernetes clusters.
| Type | What it is | Best for |
|---|---|---|
| PVC | A Persistent Volume Claim backed by a storage class on the cluster | Single-namespace workloads that need durable block or file storage |
| NFS | A network file share — either an external NFS server or a PVC exposed over NFS | Sharing data across namespaces or mounting the same volume in multiple pods simultaneously |
| CephFS | A CephFS filesystem — from an internal PVC, an external Ceph cluster, or a system storage class | High-throughput parallel access across many nodes |
Namespaces
All storage objects are namespace-scoped. A PVC created in team-a is invisible to pods in team-b. To share data across namespace boundaries, use NFS (with a PVC as the source) or CephFS — both can be mounted by pods in any namespace.
Access modes
Access modes control how many nodes can mount a volume simultaneously and whether they can write.
| Mode | Meaning |
|---|---|
| ReadWriteOnce | One node at a time, read-write |
| ReadOnlyMany | Any number of nodes, read-only |
| ReadWriteMany | Any number of nodes, read-write |
| ReadWriteOncePod | One pod at a time, read-write (stricter than ReadWriteOnce) |
Not all access modes are supported by every storage class. The UI filters available modes based on the class you select.
Storage classes
Storage classes define the provisioner, performance tier, and reclaim policy for a PVC. Vantage reads the available storage classes directly from your cluster — what you see in the UI is what your cluster supports. Your cluster administrator controls which classes are available.
NFS source modes
When creating an NFS mount, you choose how the share is sourced:
- External — Point to an existing NFS server (hostname or IP) and share path. Vantage creates a PersistentVolume backed by that server. Nothing is provisioned on the cluster.
- Internal — Select an existing PVC on the cluster. Vantage deploys an NFS server pod that exports that PVC, making it mountable from any namespace.
CephFS source modes
| Mode | How it connects |
|---|---|
| Internal | Backed by an existing PVC on the cluster |
| External | Connects to a standalone Ceph cluster using monitor addresses and client credentials |
| System | Uses a storage class to provision through a cluster-level Ceph integration (admin configuration required) |