Scaling the application after installation

Procedure

Scale the application to four replicas and expose its services to make the application zone aware and available.
```
oc expose svc/file-uploader -n my-shared-storage
```
```
oc scale --replicas=4 deploy/file-uploader -n my-shared-storage
```
```
oc get pods -o wide -n my-shared-storage
```
You should have four file-uploader pods in a few minutes. Repeat the above command until there are 4 file-uploader pods in the Running status.
Create a PVC and attach it into an application.
```
oc set volume deploy/file-uploader --add --name=my-shared-storage \
-t pvc --claim-mode=ReadWriteMany --claim-size=10Gi \
--claim-name=my-shared-storage --claim-class=ocs-storagecluster-cephfs \
--mount-path=/opt/app-root/src/uploaded \
-n my-shared-storage
```
This command:
- Creates a PVC.
- Updates the application deployment to include a volume definition.
- Updates the application deployment to attach a volume mount into the specified mount-path.
- Creates a new deployment with the four application pods.
Check the result of adding the volume.
```
oc get pvc -n my-shared-storage
```
Example Output:
```
NAME                STATUS   VOLUME                                     CAPACITY   ACCESS MODES   STORAGECLASS                AGE
my-shared-storage   Bound    pvc-5402cc8a-e874-4d7e-af76-1eb05bd2e7c7   10Gi       RWX            ocs-storagecluster-cephfs   52s
```
Notice the ACCESS MODE is set to rwx.

All the four file-uploader pods are using the same rwx volume. Without this access mode, Red Hat OpenShift does not attempt to attach multiple pods to the same Persistent Volume (PV) reliably. If you attempt to scale up the deployments that are using ReadWriteOnce (RWO) PV, the pods may get colocated on the same node.