Chapter 2. Deploying using local storage devices

Deploying OpenShift Container Storage on OpenShift Container Platform using local storage devices provided by IBM Power Systems enables you to create internal cluster resources. This results in internal provisioning of the base services, which helps to make additional storage classes available to applications.

Note

Only internal Openshift Container Storage clusters are supported on IBM Power Systems. See Planning your deployment for more information about deployment requirements.

2.1. Requirements for installing OpenShift Container Storage using local storage devices

  • You must upgrade to OpenShift Container Platform 4.6 before deploying OpenShift Container Storage 4.6. For information, see Updating OpenShift Container Platform clusters guide.
  • The Local Storage Operator version must match the Red Hat OpenShift Container Platform version in order to have the Local Storage Operator fully supported with Red Hat OpenShift Container Storage. The Local Storage Operator does not get upgraded when Red Hat OpenShift Container Platform is upgraded.
  • You must have at least three OpenShift Container Platform worker nodes in the cluster with locally attached storage devices on each of them.

    • Each of the three selected nodes must have at least one raw block device available to be used by OpenShift Container Storage.
    • The devices to be used must be empty, that is, there should be no persistent volumes (PVs), volume groups (VGs), or local volumes (LVs) remaining on the disks.
  • For minimum starting node requirements, see Resource requirements section in Planning guide.
  • You must have a minimum of three labeled nodes.

    • Each node that has local storage devices to be used by OpenShift Container Storage must have a specific label to deploy OpenShift Container Storage pods. To label the nodes, use the following command:

      $ oc label nodes <NodeNames> cluster.ocs.openshift.io/openshift-storage=''

2.2. Installing Red Hat OpenShift Container Storage Operator

You can install Red Hat OpenShift Container Storage Operator using the Red Hat OpenShift Container Platform Operator Hub. For information about the hardware and software requirements, see Planning your deployment.

Prerequisites

  • You must be logged into the OpenShift Container Platform (RHOCP) cluster.
  • You must have at least three worker nodes in the RHOCP cluster.
Note

When you need to override the cluster-wide default node selector for OpenShift Container Storage, you can use the following command in command line interface to specify a blank node selector for the openshift-storage namespace:

$ oc annotate namespace openshift-storage openshift.io/node-selector=

Procedure

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

    Figure 2.1. List of operators in the Operator Hub

    Screenshot of list of operators in the Operator Hub of the OpenShift Web Console.
  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.

    Figure 2.2. Install Operator page

    Screenshot of Ocs Install Operator page.

    After Clicking on Install button, following page will appear.

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

    1. Update Channel as stable-4.6
    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. Enable operator recommended cluster monitoring on this namespace checkbox is selected. This is required for cluster monitoring.
    5. Approval Strategy as Automatic
  5. Click Install.

    Figure 2.3. Installed Operators dashboard

    Screenshot of the installed operators.

Verification steps

  • Verify that OpenShift Container Storage Operator shows the Status as Succeeded on the Installed Operators dashboard.

2.3. Installing Local Storage Operator

Use this procedure to install the Local Storage Operator from the Operator Hub before creating OpenShift Container Storage clusters on local storage devices.

Prerequisites

  • Create a namespace called openshift-local-storage as follows:

    1. Click Administration → Namespaces in the left pane of the OpenShift Web Console.
    2. Click Create Namespace.
    3. In the Create Namespace dialog box, enter openshift-local-storage for Name.
    4. Select No restrictions option for Default Network Policy.
    5. Click Create.

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 2.4. Install Operator page

    Screenshot of Install Local storage Operator page.

    After Clicking on Install button, following page will appear.

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

    1. Update Channel as stable-4.6
    2. Installation Mode as A specific namespace on the cluster
    3. Installed Namespace as openshift-local-storage.
    4. Approval Strategy as Automatic
  5. Click Install.

    Figure 2.5. Installed Operators dashboard

    Screenshot of the installed operators.

Verification steps

  • Verify that the Local Storage Operator shows the Status as Succeeded.

2.4. Finding available storage devices

Use this procedure to identify the device names for each of the three or more worker nodes that you have labeled with the OpenShift Container Storage label cluster.ocs.openshift.io/openshift-storage='' before creating PVs for IBM Power Systems.

Procedure

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

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

    Example output:

    NAME        STATUS   ROLES    AGE     VERSION
    worker-0    Ready    worker   39h   v1.18.3+2cf11e2
    worker-1    Ready    worker   39h   v1.18.3+2cf11e2
    Worker-2    Ready    worker   39h   v1.18.3+2cf11e2
  2. Log in to each worker node that is used for OpenShift Container Storage resources and disk that has additional storage attached for each available raw block device.

    $ oc debug node/<Nodename>

    Example output:

    $ oc debug node/worker-0
    Starting pod/worker-0-debug ...
    To use host binaries, run `chroot /host`
    Pod IP: 192.168.88.11
    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
    loop0                  7:0     0    256GG  0   loop
    vda                    252:0   0     40G  0 disk
    |-vda1                 252:1   0     4M   0 part
    |-vda2                 252:2   0    384M  0 part     /boot
    `-vda4                 252:4   0   39.6G  0 part
      `-coreos-luks-root-nocrypt 253:0  0 39.6G  0 dm   /sysroot
    vdb                    252:16  0   512B   1  disk
    vdc                    252:32  0   256G   0  disk

    In this example, for worker-0, the available local device is vdc

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

2.5. Creating OpenShift Container Storage cluster on IBM Power Systems

Prerequisites

  • Ensure that all the requirements in the Requirements for installing OpenShift Container Storage using local storage devices section are met.
  • You must have three worker nodes with the same storage type and size attached to each node (for example, 200 GB) to use local storage devices on IBM Power Systems.
  • Verify your OpenShift Container Platform worker nodes are labeled for OpenShift Container Storage:

    oc get nodes -l cluster.ocs.openshift.io/openshift-storage -o jsonpath='{range .items[*]}{.metadata.name}{"\n"}'

To identify storage devices on each node, refer to Finding available storage devices.

Procedure

  1. Log into the OpenShift Web Console.
  2. In openshift-local-storage namespace Click OperatorsInstalled Operators from the left pane of the OpenShift Web Console to view the installed operators.

    Figure 2.6. Local Storage Operator page

    Screenshot of Local Storage operator dashboard.
    1. Click the Local Storage installed operator.
    2. On the Operator Details page, click the Local Volume Set link.

      Figure 2.7. Local Volume Set tab

      Screenshot of Local Volume Set tab on Local Storage Operator dashboard.
  3. Click Create Local Volume Set.

    Screenshot of Create Local Volume Set.
    1. Enter the Volume Set name. By default, Storage Class name appears for the Volume Set name.
    2. To discover available disks, you can choose one of the following:

      • All nodes to discover disks in all the nodes.
      • Select nodes to choose a subset of nodes from a list of nodes
    3. Select the Disk type.
    4. In the Advanced options, you can choose Block for the Disk mode, choose the minimum disk size equivalent to the size of additional attached disk, maximum disk size and set maximum disks limit.
    5. Click Create.

      The Create button is enabled only after you select a minimum of three nodes. Local Volume Set is created with one volume per worker node with the available disks.

  4. In openshift-storage namespace Click OperatorsInstalled Operators from the left pane of the OpenShift Web Console to view the installed operators.

    Figure 2.8. OpenShift Container Storage Operator page

    Screenshot of OpenShift Container Storage operator dashboard.
    1. Click the OpenShift Container Storage installed operator.
    2. On the Operator Details page, click the Storage Cluster link.

      Figure 2.9. Storage Cluster tab

      Screenshot of Storage Cluster tab on OpenShift Container Storage Operator dashboard.
  5. Click Create Storage Cluster.

    Screenshot of Create Cluster Service page
  6. Select Internal-Attached devices for the Select Mode.
Screenshot of storage cluster creation.
  1. Select the required storage class.
  2. Enable or Disable data encryption for the storage cluster based on the requirement.
  3. The nodes corresponding to the storage class are displayed based on the storage class that you selected from the drop down.
  4. Click Create.

    The Create button is enabled only after you select a minimum of three nodes. A new storage cluster of three volumes will be created with one volume per worker node. The default configuration uses a replication factor of 3.