Cloud Storage

Kaapana’s core services – the internal PACS (dcm4chee), MinIO, and OpenSearch – each claim a Kubernetes PersistentVolumeClaim rather than writing to a server’s disk directly.

• Single node. The microk8s hostpath provisioner backs a PVC with a plain directory on that machine’s disk, with no replication underneath it.

• Multi-node. Longhorn backs a PVC with a distributed, replicated block storage system, so the volume survives losing a node and stays reachable from wherever a pod lands.

Because the services only ever see a PVC, swapping the provider behind it – from hostpath to Longhorn, or to any CSI-compatible provider on a managed Kubernetes distribution – needs no changes to dcm4chee, MinIO, or OpenSearch themselves.

See Storage Provisioners for how each provider is set up and which of the three storage classes to pick for databases, workflow data, and bulk image data.