Chapter 2. Deploying using local storage devices

1. Understand the requirements for installing OpenShift Container Storage using local storage devices.

2. For Red Hat Enterprise Linux based hosts, enabling file system access for containers on Red Hat Enterprise Linux based nodes.

   Note

   Skip this step for Red Hat Enterprise Linux CoreOS (RHCOS).

3. Install the Red Hat OpenShift Container Storage Operator.
4. Install Local Storage Operator.
5. Find the available storage devices.
6. Creating OpenShift Container Storage cluster service on VMware.

1. Log in to the Red Hat Enterprise Linux based node and open a terminal.

2. Verify that the node has access to the rhel-7-server-extras-rpms repository.

   # subscription-manager repos --list-enabled | grep rhel-7-server

   If you do not see both rhel-7-server-rpms and rhel-7-server-extras-rpms in the output, or if there is no output, run the following commands to enable each repository.

   # subscription-manager repos --enable=rhel-7-server-rpms
   # subscription-manager repos --enable=rhel-7-server-extras-rpms

3. Install the required packages.

   # yum install -y policycoreutils container-selinux

4. Persistently enable container use of the Ceph file system in SELinux.

   # setsebool -P container_use_cephfs on

Procedure

1. Click Operators → OperatorHub in the left pane of the OpenShift Web Console.

   Figure 2.1. List of operators in the Operator Hub

   

2. Click on OpenShift Container Storage.

   You can use the Filter by keyword text box or the filter list to search for OpenShift Container Storage from the list of operators.

3. On the OpenShift Container Storage operator page, click Install.

4. On the Install Operator page, ensure the following options are selected:

   1. Update Channel as stable-4.5
   2. Installation Mode as A specific namespace on the cluster
   3. Installed Namespace as Operator recommended namespace PR openshift-storage. If Namespace openshift-storage does not exist, it will be created during the operator installation.

   4. Select Approval Strategy as Automatic or Manual. Approval Strategy is set to Automatic by default.

      • Approval Strategy as Automatic.

        Note

        When you select the Approval Strategy as Automatic, approval is not required either during fresh installation or when updating to the latest version of OpenShift Container Storage.

        1. Click Install
        2. Wait for the install to initiate. This may take up to 20 minutes.
        3. Click Operators → Installed Operators
        4. Ensure the Project is openshift-storage. By default, the Project is openshift-storage.
        5. Wait for the Status of OpenShift Container Storage to change to Succeeded.

      • Approval Strategy as Manual.

        Note

        When you select the Approval Strategy as Manual, approval is required during fresh installation or when updating to the latest version of OpenShift Container Storage.

        1. Click Install.
        2. On the Installed Operators page, click ocs-operator.
        3. On the Subscription Details page, click the Install Plan link.
        4. On the InstallPlan Details page, click Preview Install Plan.
        5. Review the install plan and click Approve.
        6. Wait for the Status of the Components to change from Unknown to either Created or Present.
        7. Click Operators → Installed Operators
        8. Ensure the Project is openshift-storage. By default, the Project is openshift-storage.
        9. Wait for the Status of OpenShift Container Storage to change to Succeeded.

Procedure

1. Click Operators → OperatorHub in the left pane of the OpenShift Web Console.
2. Search for Local Storage Operator from the list of operators and click on it.

3. Click Install.

   Figure 2.2. Install Operator page

   

4. On the Install Operator page, ensure the following options are selected

   1. Update Channel as stable-4.5
   2. Installation Mode as A specific namespace on the cluster
   3. Installed Namespace as local-storage.
   4. Approval Strategy as Automatic
5. Click Install.
6. Verify that the Local Storage Operator shows the Status as Succeeded.

Procedure

1. List and verify the name of the nodes with the OpenShift Container Storage label.

   $ oc get nodes -l cluster.ocs.openshift.io/openshift-storage=

   Example output:

   NAME        STATUS   ROLES    AGE    VERSION
   compute-0   Ready    worker   106m   v1.18.3+2cf11e2
   compute-1   Ready    worker   106m   v1.18.3+2cf11e2
   compute-2   Ready    worker   106m   v1.18.3+2cf11e2

2. Log in to each node that is used for OpenShift Container Storage resources and find the unique by-id device name for each available raw block device.

   $ oc debug node/<Nodename>

   Example output:

   $ oc debug node/compute-0
   Starting pod/compute-0-debug ...
   To use host binaries, run `chroot /host`
   Pod IP: 10.1.50.36
   If you don't see a command prompt, try pressing enter.
   sh-4.2# chroot /host
   sh-4.4# lsblk
   NAME                         MAJ:MIN RM   SIZE RO TYPE MOUNTPOINT
   sda                            8:0    0   120G  0 disk
   |-sda1                         8:1    0   384M  0 part /boot
   |-sda2                         8:2    0   127M  0 part /boot/efi
   |-sda3                         8:3    0     1M  0 part
   `-sda4                         8:4    0 119.5G  0 part
     `-coreos-luks-root-nocrypt 253:0    0 119.5G  0 dm   /sysroot
   nvme0n1                      259:0    0   1.5T  0 disk

   In this example, for compute-0, the available local device is nvme0n1.

3. Identify the unique ID for each of the devices selected in Step 2.

   sh-4.4#
   ls -l /dev/disk/by-id/ | grep nvme0n1
   lrwxrwxrwx. 1 root root 13 Aug 19 06:41 nvme-Dell_Express_Flash_NVMe_P4610_1.6TB_SFF_PHLN951601QF1P6AGN -> ../../nvme0n1
   lrwxrwxrwx. 1 root root 13 Aug 19 06:41 nvme-eui.01000000010000005cd2e4895e0e5251 -> ../../nvme0n1

   In the above example, the ID for the local device 'nvme0n1` is

   nvme-eui.01000000010000005cd2e4895e0e5251

4. Repeat the above step to identify the device ID for all the other nodes that have the storage devices to be used by OpenShift Container Storage. See this Knowledge Base article for more details.

Procedure

1. Create the LocalVolume CR for block PVs.

   Example of LocalVolume CR local-storage-block.yaml using OpenShift Container Storage label as node selector:

   apiVersion: local.storage.openshift.io/v1
   kind: LocalVolume
   metadata:
     name: local-block
     namespace: local-storage
     labels:
       app: ocs-storagecluster
   spec:
     nodeSelector:
       nodeSelectorTerms:
       - matchExpressions:
           - key: cluster.ocs.openshift.io/openshift-storage
             operator: In
             values:
             - ""
     storageClassDevices:
       - storageClassName: localblock
         volumeMode: Block
         devicePaths:
           - /dev/disk/by-id/nvme-eui.01000000010000005cd2e4895e0e5251   # <-- modify this line
           - /dev/disk/by-id/nvme-eui.01000000010000005cd2e4ea2f0f5251   # <-- modify this line
           - /dev/disk/by-id/nvme-eui.01000000010000005cd2e4de2f0f5251   # <-- modify this line

2. Create LocalVolume CR for block PVs.

   $ oc create -f local-storage-block.yaml

   Example output:

   localvolume.local.storage.openshift.io/local-block created

3. Check if the pods are created.

   $ oc -n local-storage get pods

   Example output:

   NAME                                      READY   STATUS    RESTARTS   AGE
   local-block-local-diskmaker-5brzv         1/1     Running   0          31s
   local-block-local-diskmaker-8sxcs         1/1     Running   0          31s
   local-block-local-diskmaker-s7s9p         1/1     Running   0          31s
   local-block-local-provisioner-9cbw8       1/1     Running   0          31s
   local-block-local-provisioner-cpddv       1/1     Running   0          31s
   local-block-local-provisioner-f6h7h       1/1     Running   0          31s
   local-storage-operator-75b9776b75-vwdzh   1/1     Running   0          12m

4. Check the new localblock StorageClass.

   $ oc get sc | grep localblock

   Example output:

   localblock       kubernetes.io/no-provisioner   Delete          WaitForFirstConsumer   false                  96s

5. Check the PVs that are created with the Available status.

   $ oc get pv

   Example output:

   NAME                CAPACITY   ACCESS MODES   RECLAIM POLICY   STATUS      CLAIM   STORAGECLASS   REASON   AGE
   local-pv-264b0256   1490Gi     RWO            Delete           Available           localblock              108s
   local-pv-8b0e9b53   1490Gi     RWO            Delete           Available           localblock              99s
   local-pv-8dcc8c60   1490Gi     RWO            Delete           Available           localblock              98s

6. Create the OpenShift Container Storage Cluster Service that uses the localblock Storage Class.

   1. Log into the OpenShift Web Console.
   2. Click Operators → Installed Operators from the OpenShift Web Console to view the installed operators. Ensure that the Project selected is openshift-storage.

   3. On the Installed Operators page, click Openshift Container Storage.

      Figure 2.3. OpenShift Container Storage Operator page

      

   4. On the Installed Operators → Operator Details page, perform either of the following to create a Storage Cluster Service.

      • On the Details tab → Provided APIs → OCS Storage Cluster, click Create Instance.

        Figure 2.4. Operator Details Page

        

      • Alternatively, select the Storage cluster tab and click Create OCS Cluster Service.

        Figure 2.5. Storage Cluster tab

        

   5. On the Create Storage Cluster page, ensure that the following options are selected:

      
      • Leave Select Mode as Internal.

      • In the Nodes section, for the use of OpenShift Container Storage service, select a minimum of three or a multiple of three worker nodes from the available list.

        It is recommended that the worker nodes are spread across three different physical nodes, racks or failure domains for high availability.

        Note

        • To find specific worker nodes in the cluster, you can filter nodes on the basis of Name or Label.

          • Name allows you to search by name of the node
          • Label allows you to search by selecting the predefined label
        • Use vCenter anti-affinity to align OpenShift Container Storage rack labels with physical nodes and racks in the data center to avoid scheduling two worker nodes on the same physical chassis.

        For minimum starting node requirements, see Resource requirements section in Planning guide.

      • Select localblock from the Storage Class dropdown list.

   6. Click Create.

      Note

      The Create button is enabled only after selecting a minimum of three worker nodes.

      Upon successful deployment, a storage cluster with three storage devices gets created. These devices get distributed across three of the selected nodes. The configuration uses a replication factor of 3. To scale the initial cluster, see Scaling storage nodes.