BLOG11: Available StorageClass

BLOG 50: Available StorageClass Provisioner

1. NFS StorageClass — RWX, dynamic provisioning (already done)

Why demo it?

• Best example of ReadWriteMany

• Works on ANY cluster (on-prem, KinD, K3s)

• Shows folder creation magic ✨

SC example:

apiVersion: storage.k8s.io/v1
kind: StorageClass
metadata:
  name: nfs-client
provisioner: k8s-sigs.io/nfs-subdir-external-provisioner
reclaimPolicy: Delete

Cool demo ideas:

• Two pods writing to same PVC

• PVC fills up → observe NFS behavior

• Files show up instantly in NFS folder

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2. HostPath Provisioner — simple, for single-node clusters

Why demo?

• Shows how Kubernetes can use raw host filesystem

• Easy to break, easy to fix, great for teaching

• Perfect for minikube/k3s demos

SC example:

apiVersion: storage.k8s.io/v1
kind: StorageClass
metadata:
  name: hostpath
provisioner: kubevirt.io/hostpath-provisioner
reclaimPolicy: Delete
volumeBindingMode: WaitForFirstConsumer

Demo ideas:

• Show PVC binding waits until Pod is scheduled

• Open node path → see automatically created folders

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3. Local Persistent Storage (Local PV) — Fastest performance

Why demo?

• Shows SSD/NVMe power

• Demonstrates node affinity

• Very realistic for bare-metal clusters

StorageClass:

apiVersion: storage.k8s.io/v1
kind: StorageClass
metadata:
  name: local-storage
provisioner: kubernetes.io/no-provisioner
volumeBindingMode: WaitForFirstConsumer

Local PV:

apiVersion: v1
kind: PersistentVolume
metadata:
  name: local-pv-1
spec:
  volumeMode: Filesystem
  capacity:
    storage: 10Gi
  accessModes:
    - ReadWriteOnce
  storageClassName: local-storage
  local:
    path: /mnt/disks/disk1
  nodeAffinity:
    required:
      nodeSelectorTerms:
        - matchExpressions:
            - key: kubernetes.io/hostname
              operator: In
              values:
                - k8s-node-1

Demo ideas:

• Show Pod scheduling to the specific node

• Disable the node → PVC becomes stuck

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4. AWS EBS CSI StorageClass — cloud-native demo

Great when using real AWS or a mock environment.

Why demo?

• Shows cloud block volumes

• Demonstrates gp2, gp3, io2, throughput settings

Example (gp3):

apiVersion: storage.k8s.io/v1
kind: StorageClass
metadata:
  name: gp3
provisioner: ebs.csi.aws.com
parameters:
  type: gp3
  iops: "3000"
  throughput: "125"
reclaimPolicy: Delete
volumeBindingMode: WaitForFirstConsumer

Demo ideas:

• Explain difference in performance parameters

• Use small pods to benchmark IOPS

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5. Ceph RBD (rook) — highly scalable storage

Why demo?

• Production-grade

• Amazing for showing replicating block storage

• Shows how CSI drivers work

• Very popular in on-prem clusters

SC example:

apiVersion: storage.k8s.io/v1
kind: StorageClass
metadata:
  name: rook-ceph-block
provisioner: rook-ceph.rbd.csi.ceph.com
parameters:
  clusterID: rook-ceph
  pool: replicapool
  imageFeatures: layering
reclaimPolicy: Delete
allowVolumeExpansion: true

Demo ideas:

• Expand a PVC live (e.g., 1Gi → 5Gi)

• Kill OSDs → show Ceph healing itself

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6. GlusterFS StorageClass — distributed, expandable

SC example:

apiVersion: storage.k8s.io/v1
kind: StorageClass
metadata:
  name: gluster-heketi
provisioner: kubernetes.io/glusterfs
parameters:
  resturl: "http://heketi-storage.gluster.svc:8080"

Demo idea:

• Show automatic provisioning across nodes

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7. Longhorn Storage — cloud-native block storage for on-prem

Why demo?

• Nice dashboard

• Self-healing

• Snapshots, backups built-in

SC example:

apiVersion: storage.k8s.io/v1
kind: StorageClass
metadata:
  name: longhorn
provisioner: driver.longhorn.io
allowVolumeExpansion: true
reclaimPolicy: Delete

Demo:

• Damage nodes → volume self-replicates

• Show backup/restore

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8. OpenEBS — per-workload storage engine

Engines you can demo:

• Jiva

• cStor

• LocalPV

SC example (OpenEBS Jiva):

apiVersion: storage.k8s.io/v1
kind: StorageClass
metadata:
  name: openebs-jiva
provisioner: jiva.csi.openebs.io

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9. CSI HostPath Driver — CSI demo for teaching

Great for explaining CSI because it’s tiny and simple.

SC:

apiVersion: storage.k8s.io/v1
kind: StorageClass
metadata:
  name: csi-hostpath-sc
provisioner: hostpath.csi.k8s.io

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10. EmptyDir vs PersistentVolume demo

Even though emptyDir is not a StorageClass, it's a PERFECT compare-demo:

Demo:

• Kill a pod → see emptyDir wiped

• PVC persists

This explains storage persistence beautifully.

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Recommended Combination for a Powerful Demo Set

Storage Type	What It Shows
NFS	RWX, dynamic provisioning
HostPath	Basic provisioning on on-prem
LocalPV	Node affinity + fastest storage
EBS (Cloud)	Cloud block volumes
Longhorn	Cloud-native features
EmptyDir	Ephemeral storage

This covers 100% of what students / trainees / clients want to see.