Creating Persistent File System Storage

The Private Cloud Appliance File Storage service provides a durable, scalable, distributed, enterprise-grade network file system. See "Creating a File System, Mount Target, and Export" in the File System Storage chapter in the Oracle Private Cloud Appliance User Guide to create a mount target, file system, and file system export on the Private Cloud Appliance. Then use the kubectl command to create the storage class, persistent volume, and persistent volume claim.

Create a mount target.

Important:

To ensure that the mount target can be reached from worker nodes, create the mount target on the subnet that has configuration like the "worker" subnet described in Creating an OKE Worker Subnet. Ensure that TCP port 2049 to the NFS server is open on that subnet.

If you do not create the mount target on the worker subnet, you might need to set security rules to ensure that the worker nodes can reach the mount target.

See "Creating a Mount Target" in the File System Storage chapter in the Oracle Private Cloud Appliance User Guide.

Note the export set OCID and mount target OCID. The export set OCID is required to create the file system export, and the mount target OCID is required to create the storage class. See Steps 3 and 4.

You can have only one mount target per VCN.
Create a file system.

See "Creating a File System" in the File System Storage chapter in the Oracle Private Cloud Appliance User Guide.

You can create only one file system per VCN. You can have multiple storage classes, persistent volumes, and persistent volume claims per cluster, and they all share one NFS.
Create a file system export to associate the mount target with the file system.

See "Creating an Export for a File System" in the File System Storage chapter in the Oracle Private Cloud Appliance User Guide.
- Specify the export set OCID from the output from creating the mount target.
- Specify the longest CIDR (smallest network) in the CIDR range that you specified when you created the "worker" subnet as described in Creating an OKE Worker Subnet.
Note the export path and the mount target IP address.
Create a storage class, specifying the mount target OCID from the output of the create mount target step.
```
$ kubectl create -f sc.yaml
```
The following is the content of the sc.yaml file:
```
kind: StorageClass
apiVersion: storage.k8s.io/v1
metadata:
  name: pca-fss
provisioner: fss.csi.oraclecloud.com
parameters:
  mntTargetId: ocid1.mounttarget.unique_ID
```
The values of the apiVersion and provisioner properties are standard. The value of the storage class name in the metadata section is user-specified. You can create more than one storage class per mount target, and the storage class name is used in the following steps to create a persistent volume and persistent volume claim.

Use the get sc subcommand to view information about the new storage class:
```
$ kubectl get sc
```
Create a persistent volume, specifying the storage class name, the export path, and the mount target IP address.

The storage class name is in the metadata in the sc.yaml file in the preceding step. The export path and the mount target IP address are output from the create file system export step. See Step 3 above.
```
$ kubectl create -f pv.yaml
```
The following is the content of the pv.yaml file:
```
apiVersion: v1
kind: PersistentVolume
metadata:
  name: fss-pv
spec:
  storageClassName: pca-fss
  capacity:
    storage: 200Gi
  accessModes:
    - ReadWriteMany
  mountOptions:
    - nosuid
  nfs:
    server: mount_target_IP_address
    path: "/export/unique_ID"
    readOnly: false
```
The persistent volume name in the metadata section is user-specified. You can have more than one persistent volume in a storage class.

In the nfs section, the server value is the mount target IP address, and the path value is the export path.

Use the get pv subcommand to view information about the new persistent volume:
```
$ kubectl get pv
NAME    CAPACITY  ACCESS MODES  RECLAIM POLICY  STATUS  CLAIM            STORAGECLASS  REASON  AGE
fss-pv  200Gi     RWX           Retain          Bound   default/fss-pvc  pca-fss               20h
```
Create a persistent volume claim, specifying the persistent volume name and the storage class name.

The persistent volume name and storage class name are in the output of the get pv command.

Wait for the PVC status to be Bound before using this storage.
```
kubectl create -f pvc.yaml
```
The following is the content of the pvc.yaml file:
```
apiVersion: v1
kind: PersistentVolumeClaim
metadata:
  name: fss-pvc
spec:
  storageClassName: pca-fss
  accessModes:
    - ReadWriteMany
  resources:
    requests:
      storage: 200Gi
  volumeName: fss-pv
```
The persistent volume claim name in the metadata section is user-specified. You can have more than one persistent volume claim on a persistent volume.

The value of the accessModes property must be ReadWriteMany.

The value of the storage property must be at least 50 gigabytes.

Run the following command to view information about the new persistent volume claim:
```
$ kubectl get pvc
NAME      STATUS   VOLUME   CAPACITY   ACCESSMODES   STORAGECLASS   AGE
fss-pvc   Bound    fss-pv   200Gi      RWX           pca-fss        2h
```

Use the PVC when creating other objects, such as pods.

For example, you could create a new pod from the following pod definition, which instructs the system to use the fss-pvc PVC as the nginx volume, which is mounted by the pod at /persistent-storage:

apiVersion: v1
kind: Pod
metadata:
  name: fss-dynamic-app
spec:
  containers:
    - name: nginx
      image: nginx:latest
      ports:
        - name: http
          containerPort: 80
      volumeMounts:
        - name: persistent-storage
          mountPath: /usr/share/nginx/html
  volumes:
  - name: persistent-storage
    persistentVolumeClaim:
      claimName: fss-pvc

Run the following command to verify that the pod is using the new PVC:

$ kubectl describe pod nginx