## 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

---

# 🧊 **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

---

# ⚡ **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

---

# ☁️ **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

---

# 🔥 **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

---

# ♻️ **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

---

# 🧊 **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

---

# 🏰 **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

---

# 🌊 **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

---

# 🌕 **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.

---

# ⭐ **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.**