Introduction

A Unity LUN that is provisioned to the worker nodes cannot be used directly as a storage option for the image registry. You must create a PV and PVC mappings to the Unity LUN.

Ensure that the prerequisites have been met (see Prerequisites for using Unity storage) and then perform the tasks in the following procedures:

• Adding worker nodes in Unity hosts
• Creating a LUN and mapping it to the worker nodes
• Creating a PV using a Unity LUN
• Creating a PVC and pod

In the following sample, the IP address for targetPortal and the IQN for iqn is from the Unity Unisphere UI, as shown in the following figure.

Note: In the Unisphere UI, under STORAGE, select Block, and then click the iSCSI Interfaces tab.

Figure 20.          iSCSI IP address and IQN info in Unisphere

To create a PV:

1. Create a PV YAML file using the following sample:

 [core@csah ~]$ cat podpv.yaml

apiVersion: v1

kind: PersistentVolume

metadata:

  name: podpv

spec:

  capacity:

    storage: 20G

  accessModes:

  - ReadWriteOnce

  iscsi:

    targetPortal: 100.82.47.29:3260

    iqn: iqn.1992-04.com.emc:cx.apm00193820970.a7

    lun: 1

    fsType: ext4

    readOnly: false

2. Create a PV:

[core@csah ~]$ oc create -f podpv.yaml

persistentvolume/podpv created

Creating a PVC and pod

A PVC is used in the image registry operator as a storage option for the image registry. Create a PVC and then the pod as follows:

1. Create a PVC YAML file using the following sample file:

[core@csah ~]$ cat podpvc.yaml

apiVersion: v1

kind: PersistentVolumeClaim

metadata:

  name: podpvc

spec:

  accessModes:

  - ReadWriteOnce

  resources:

    requests:

      storage: 20G

2. Create a PVC:

[core@csah ~]$ oc create -f podpv.yaml

persistentvolume/podpv created

3. Create a YAML file with the following content to create a pod that will use the PVC as a mount point:

[core@csah ~]$ cat podunity.yaml

apiVersion: v1

kind: Pod

metadata:

  name: unitypod

spec:

  containers:

  - name: nginx

    image: nginx

    volumeMounts:

    - mountPath: "/var/www/html"

      name: unitypvc

  volumes:

  - name: unitypvc

    persistentVolumeClaim:

      claimName: podpvc

4. Create a pod:

[core@csah ~]$ oc create -f podunity.yaml

pod/unitypod created

If the pod creation fails, run oc describe pod unitypod to check for errors. Under Events, a FailedMount error is displayed if the block storage is not visible in the worker node where the pod will be started. To address this issue, run sudo rescan-scsi-bus.sh in all worker nodes as user core.

Ensure that the LUN number that is displayed matches the LUN number on the worker node (ls /dev/disk/by-path).

5. Validate the pod status and mount point:

[core@csah ~]$ oc get pods

NAME       READY   STATUS    RESTARTS   AGE

unitypod   1/1     Running   0          31m

[core@csah ~]$ oc exec -it unitypod -- df -h /var/www/html

Filesystem      Size  Used Avail Use% Mounted on

/dev/sdc         20G   45M   20G   1% /var/www/html