Chapter 3. Scaling out storage capacity

To scale out storage capacity, you need to perform the following steps:

  • Add a new node
  • Verify that the new node is added successfully
  • Scale up the storage capacity
Note

OpenShift Container Storage does not support heterogeneous OSD sizes.

3.1. Adding a node

You can add nodes to increase the storage capacity when existing worker nodes are already running at their maximum supported OSDs, which is increment of 3 OSDs of the capacity selected during initial configuration.

Depending on the type of your deployment, you can choose one of the following procedures to add a storage node:

3.1.1. Adding a node on an installer-provisioned infrastructure

Use this proecdure to add a node on an AWS or Azure installer provisioned infrastructure.

Prerequisites

  • You must be logged into OpenShift Container Platform (RHOCP) cluster.

Procedure

  1. Navigate to Compute → Machine Sets.
  2. On the machine set where you want to add nodes, select Edit Machine Count.
  3. Add the amount of nodes, and click Save.
  4. Click Compute → Nodes and confirm if the new node is in Ready state.

  5. Apply the OpenShift Container Storage label to the new node.

    1. For the new node, Action menu (⋮) → Edit Labels.
    2. Add cluster.ocs.openshift.io/openshift-storage and click Save.
Note

It is recommended to add 3 nodes each in different zones. You must add 3 nodes and perform this procedure for all of them.

Verification steps

3.1.2. Adding a node on an user-provisioned infrastructure

Use this procedure to add a node on an AWS or VMware user-provisioned infrastructure.

Prerequisites

  • You must be logged into OpenShift Container Platform (RHOCP) cluster.

Procedure

  1. Depending on whether you are adding a node on an AWS user provisioned infrastructure or a VMware user-provisioned infrastructure, perform the following steps:

    • For AWS

      1. Create a new AWS machine instance with the required infrastructure. See Platform requirements.
      2. Create a new OpenShift Container Platform node using the new AWS machine instance.

    • For VMware:

      1. Create a new VM on vSphere with the required infrastructure. See Platform requirements.
      2. Create a new OpenShift Container Platform worker node using the new VM.

  2. Check for certificate signing requests (CSRs) related to OpenShift Container Storage that are in Pending state: 

    $ oc get csr

  3. Approve all required OpenShift Container Storage CSRs for the new node: 

    $ oc adm certificate approve <Certificate_Name>
  4. Click Compute → Nodes, confirm if the new node is in Ready state.

  5. Apply the OpenShift Container Storage label to the new node using any one of the following:

    From User interface
    1. For the new node, click Action Menu (⋮) → Edit Labels
    2. Add cluster.ocs.openshift.io/openshift-storage and click Save.
    From Command line interface

    • Execute the following command to apply the OpenShift Container Storage label to the new node: 

      $ oc label node <new_node_name> cluster.ocs.openshift.io/openshift-storage=""
      Note

      It is recommended to add 3 nodes each in different zones. You must add 3 nodes and perform this procedure for all of them.

Verification steps

3.1.3. Adding a node using a local storage device

Use this procedure to add a node on bare metal, IBM Power Systems, IBM Z or LinuxONE, Amazon EC2, and VMware infrastructures.

Important

Scaling storage nodes for Amazon EC2 infrastructure is a Technology Preview feature. Technology Preview features are not supported with Red Hat production service level agreements (SLAs) and might not be functionally complete. Red Hat does not recommend using them in production. These features provide early access to upcoming product features, enabling customers to test functionality and provide feedback during the development process.

Prerequisites

  • You must be logged into the OpenShift Container Platform (RHOCP) cluster.
  • If you upgraded to OpenShift Container Storage 4.6 from a previous version, ensure that you have followed post-upgrade procedures to create the LocalVolumeDiscovery object. See Post-update configuration changes for details.
  • You must have three OpenShift Container Platform worker nodes with the same storage type and size attached to each node (for example, 2TB SSD or 2TB NVMe drive) as the original OpenShift Container Storage StorageCluster was created with.
  • If you have upgraded from a previous version of OpenShift Container Storage, create a LocalVolumeSet object to enable automatic provisioning of devices as described in Post-update configuration changes.

Procedure

  1. Depending on whether you are adding a node on bare metal, IBM Power Systems, IBM Z or LinuxONE, Amazon EC2, or VMware infrastructure, perform the following steps:

    • For Amazon EC2

      1. Create a new Amazon EC2 I3 machine instance with the required infrastructure. See Creating a MachineSet in AWS and Platform requirements.
      2. Create a new OpenShift Container Platform node using the new Amazon EC2 I3 machine instance.

    • For VMware:

      1. Create a new VM on vSphere with the required infrastructure. See Platform requirements.
      2. Create a new OpenShift Container Platform worker node using the new VM.

    • For bare metal:

      1. Get a new bare metal machine with the required infrastructure. See Platform requirements.
      2. Create a new OpenShift Container Platform node using the new bare metal machine.

    • For IBM Power Systems:

      1. Get a new IBM Power machine with the required infrastructure. See Platform requirements.
      2. Create a new OpenShift Container Platform node using the new IBM Power machine.

    • For IBM Z or LinuxONE:

      1. Get a new IBM Z or LinuxONE machine with the required infrastructure. See Platform requirements.
      2. Create a new OpenShift Container Platform node using the new IBM Z or LinuxONE machine.

  2. Check for certificate signing requests (CSRs) related to OpenShift Container Storage that are in Pending state: 

    $ oc get csr

  3. Approve all required OpenShift Container Storage CSRs for the new node: 

    $ oc adm certificate approve <Certificate_Name>
  4. Click Compute → Nodes, confirm if the new node is in Ready state.

  5. Apply the OpenShift Container Storage label to the new node using any one of the following:

    From User interface
    1. For the new node, click Action Menu (⋮) → Edit Labels
    2. Add cluster.ocs.openshift.io/openshift-storage and click Save.
    From Command line interface

    • Execute the following command to apply the OpenShift Container Storage label to the new node: 

      $ oc label node <new_node_name> cluster.ocs.openshift.io/openshift-storage=""

  6. Click Operators → Installed Operators from the OpenShift Web Console.

    From the Project drop-down list, make sure to select the project where the Local Storage Operator is installed.

  7. Click on Local Storage.
  8. Click the Local Volume Discovery tab
  9. Beside the LocalVolumeDiscovery, click Action menu (⋮) → Edit Local Volume Discovery.
  10. In the YAML, add the hostname of the new node in the values field under the node selector.
  11. Click Save.
  12. Click the Local Volume Sets tab.
  13. Beside the LocalVolumeSet, click Action menu (⋮) → Edit Local Volume Set.

  14. In the YAML, add the hostname of the new node in the values field under the node selector.

    Figure 3.1. YAML showing the addition of new hostnames

    Screenshot of YAML showing the addition of new hostnames.
  15. Click Save.
Note

It is recommended to add 3 nodes each in different zones. You must add 3 nodes and perform this procedure for all of them.

Verification steps

3.1.4. Verifying the addition of a new node

  1. Execute the following command and verify that the new node is present in the output: 

    $ oc get nodes --show-labels | grep cluster.ocs.openshift.io/openshift-storage= |cut -d' ' -f1

  2. Click Workloads → Pods, confirm that at least the following pods on the new node are in Running state:

    • csi-cephfsplugin-*
    • csi-rbdplugin-*

3.2. Scaling up storage capacity

To scale up storage capacity, see Scaling up storage by adding capacity.