In a previous blog post, I mentioned that the Trident 25.02 release supports provisioning block storage on ONTAP-based systems using the Fiber Channel (FC) protocol. In this post, I'll show you how to leverage the FC protocol to provision persistent storage for both containers and VMs on the OpenShift Container Platform.
Introduction
Prior to the Trident 25.02 release, users could provision block storage using iSCSI or NVMe/TCP protocols. However, many NetApp ONTAP customers run their workloads on VMware and have significant investments in Fiber Channel networks. With the Trident 25.02 release, these customers can modernize their platforms or applications while continuing to use their FC networks for storage provisioning. Let's see how this is done.
Prerequisites
For this example, I have an OpenShift cluster version 4.17 and have installed Trident 25.2.1 using the Red Hat certified Trident operator.
Step 1: Create a Trident Backend Configuration
First, create a Trident backend configuration file that specifies the FC protocol. Below is a sample tbc-fc.yaml file:
apiVersion: v1
kind: Secret
metadata:
name: tbc-fc-secret
type: Opaque
stringData:
username: admin
password: <password>
---
apiVersion: trident.netapp.io/v1
kind: TridentBackendConfig
metadata:
name: tbc-fc
spec:
version: 1
storageDriverName: ontap-san
managementLIF: <cluster_mgmt_IP>
backendName: tbc-fc
svm: openshift-fc
sanType: fcp
storagePrefix: demofc
defaults:
nameTemplate: "{{ .config.StoragePrefix }}_{{ .volume.Namespace }}_{{ .volume.RequestName }}"
credentials:
name: tbc-fc-secret
Replace <password> and <cluster_mgmt_IP> with your actual credentials and cluster management IP address. Apply the backend configuration:
oc create -f tbc-fc.yaml -n trident
Step 2: Create a Storage Class
Next, create a storage class that uses the tbc-fc backend. Below is the sc-fc.yaml file:
apiVersion: storage.k8s.io/v1
kind: StorageClass
metadata:
name: sc-fc
provisioner: csi.trident.netapp.io
parameters:
backendType: "ontap-san"
media: "ssd"
provisioningType: "thin"
fsType: ext4
snapshots: "true"
allowVolumeExpansion: true
Apply the storage class configuration:
oc create -f sc-fc.yaml
Step 3: Create a VolumeSnapshotClass
Create a VolumeSnapshotClass to manage snapshots. Below is the snapshotclass.yaml file:
apiVersion: snapshot.storage.k8s.io/v1
kind: VolumeSnapshotClass
metadata:
name: trident-snapshotclass
driver: csi.trident.netapp.io
deletionPolicy: Retain
Apply the volumeSnapshotClass configuration:
oc create -f snapshotclass.yaml
Step 4: Set default storage class and volumeSnapshotClass
Set the sc-fc storage class to be the default storage class by setting the annotation:
storageclass.kubernetes.io/is-default-class: true
Also set the trident-snapshotclass to be the default snapshot class by setting the annotations as follows:
snapshot.storage.kubernetes.io/is-default-class: true
You can do the above either from the console or from the CLI. I have shown below screenshots when the settings are done from the console.
Here is the backend configuration, storage class and the volumeSnapshot class set in the cluster from the console:
Creating VMs on OpenShift Virtualization using Storage class san-fc
Install OpenShift Virtualization and from the user interface under Virtualization, click on Virtual machines to create a new VM.
Click on Create Virtual machine.
Select From template and then select the OS. If you pick the OS that says Source available, the golden image already available in the cluster is used to create a VM. For this example, click on Fedora VM.
Now, click on Customize VirtualMachine button. Use all the defaults on this page and click on CustomizeVirtualMachine.
Select the Disks tab. There is a rootdisk for this VM. Click on the 3 dots for this disk, and select edit. Note that the storage class is sc-fc (since it was set as the default).
Add another disk.(empty disk) and note that the storage class is automatically selected as sc-fc and Apply optimized StorageProfile settings is selected.
Note: The apply optimized StorageProfile settings ensures that the Access Mode is RWX and VolumeMode is Block. Trident supports RWX access mode in volume mode Block. RWX is required if you need to do Live migration of the VM from one node to another at a later point.
Click on Create Virtual Machine.
The virtual machine goes from Provisioning to Starting to Running status.
Now, you can review the PVCs created for the VM either from the console or from the CLI. Here I am showing them using the CLI.
You can see that the storage class used for the pvcs is san-fc.
Now you can verify in the ONTAP storage system that the volume and the lun is created for each trident persistent volume of the VM.
Note: The volume name in ONTAP corresponding to the pv can be found by using the describe pv command.
Creating Applications on OpenShift Container Platform Using Storage Class sc-fc
Now that we have set up the backend configuration and storage class, let's create a PostgreSQL application that uses the sc-fc storage class for its persistent storage.
Step 1: Create a PostgreSQL Deployment
Create a postgres.yaml file with the following yaml:
apiVersion: apps/v1
kind: Deployment
metadata:
name: postgres
spec:
replicas: 1
selector:
matchLabels:
app: postgres
template:
metadata:
labels:
app: postgres
spec:
containers:
- name: postgres
image: postgres:14
env:
- name: POSTGRES_USER
value: "admin"
- name: POSTGRES_PASSWORD
value: "adminpass"
- name: POSTGRES_DB
value: "mydb"
- name: PGDATA
value: "/var/lib/postgresql/data/pgdata"
ports:
- containerPort: 5432
volumeMounts:
- name: postgres-storage
mountPath: /var/lib/postgresql/data
volumes:
- name: postgres-storage
persistentVolumeClaim:
claimName: postgres-pvc
---
apiVersion: v1
kind: PersistentVolumeClaim
metadata:
name: postgres-pvc
spec:
accessModes:
- ReadWriteOnce
resources:
requests:
storage: 5Gi
storageClassName: sc-fc
---
apiVersion: v1
kind: Service
metadata:
name: postgres
spec:
selector:
app: postgres
ports:
- protocol: TCP
port: 5432
targetPort: 5432
type: ClusterIP
Apply the configuration to create the PostgreSQL deployment, PVC, and service:
oc apply -f postgres.yaml
Step 2: Verify the Deployment
After applying the configuration, verify that the PostgreSQL pod is running and that the PVC is bound. You can check the status using the following commands:
You can verify the volumes created in the ONTAP system using the ONTAP CLI as shown previously.
Conclusion
The Fiber Channel network is widely used by many customers, and the ability to use Trident to provision storage using the FC protocol is a significant benefit. This capability allows organizations to retain their investments in FC networks while modernizing their workloads or migrating VM workloads to modern container-based platforms like OpenShift.
NetApp continues to empower its customers by providing robust, enterprise-grade storage solutions that are easy to deploy and manage. Whether you're running modern application workloads or virtual machine workloads on OpenShift, the new Trident 25.02 offers a streamlined, efficient, and cost-effective way to enhance your storage capabilities.
By following the steps outlined in this post, you can leverage the Fiber Channel protocol to provision persistent storage for your applications and VMs on OpenShift, ensuring high performance and reliability for your critical workloads.
