Storage

The cluster uses multiple storage backends for different workload requirements.

Storage Classes

Class	Backend	Access Modes	Use Case
openebs-hostpath	OpenEBS	RWO	Database volumes, high-performance local storage
nfs-fast	CSI Driver NFS	RWX	VM disks, shared media, multi-node access

OpenEBS

OpenEBS provides cloud-native local storage:

• hostpath provisioner for fast local volumes
• Used by PostgreSQL, Dragonfly, and other stateful workloads
• CDI scratch space for VM disk imports

kubernetes/apps/openebs-system/openebs/
├── app/
│   ├── helmrelease.yaml
│   ├── ocirepository.yaml
│   └── kustomization.yaml
└── ks.yaml

NFS Storage

CSI Driver NFS provides shared network storage:

• ReadWriteMany support for multi-node access
• Used for VM disks (enables live migration)
• Used for shared media storage
• NFS-scaler component prevents pods from crash-looping when NFS is unavailable

Backup System

VolSync

VolSync handles volume replication and backup:

• Backs up PersistentVolumeClaims to S3-compatible storage
• Scheduled daily at 2 AM
• Component available at kubernetes/components/volsync/

Garage

Garage provides S3-compatible storage as the backup destination:

• Self-hosted within the cluster
• Used by VolSync and CloudNative-PG backups

Kopia

Kopia serves as the backup repository:

• Deduplication and encryption
• Works with VolSync for volume-level backups

Snapshot Controller

The snapshot-controller enables volume snapshots for point-in-time recovery.

NFS Scaler Component

Located in kubernetes/components/nfs-scaler/, this KEDA-based component monitors NFS availability:

• Queries Prometheus for probe_success{instance=~".+:2049"} metric
• Scales deployments 0 → 1 when NFS is available
• Scales down to 0 when NFS is unavailable
• Prevents crash-loop storms when NFS is down

Apply to any app that mounts NFS volumes.