Adding nodes to an existing cluster

Adding nodes

To add a node:

• Ensure the node that belongs to the existing Machine Config Pool configured to include the kernel-devel extensions. This was configured as a prerequisite to IBM Storage Scale container native installation, and defaults to Red Hat OpenShift worker nodes. For more information, see Red Hat OpenShift Container Platform.
• Ensure the node has a node selector that matches the existing cluster's node selector. For more information, see Node selectors.

When the node selector is recognized by the IBM Storage Scale Operator, a pod will be created on the new node and will go to running state within a few minutes.

Post node addition tasks

Verify node addition

Check the progress of the creation of the new pod by entering the following command:

kubectl get pods -n ibm-spectrum-scale

Ensure the new pod is ready by entering the following command:

kubectl exec -n ibm-spectrum-scale \
$(kubectl get pods -lapp.kubernetes.io/name=core -n ibm-spectrum-scale -ojsonpath="{.items[0].metadata.name}") \
-- mmgetstate -a

The output appears as shown:

 Node number  Node name        GPFS state
-------------------------------------------
       1      worker1          active
       2      new node         arbitrating
       3      worker0          active

Once the pod has finished arbitrating and enters the active state, CSI will automatically be configured for use by the pod by the IBM Storage Scale and CSI Operators. Once CSI has completed configuration, then the newly added node can now be used for running applications.

Add quorum nodes (optionally)

When adding nodes it may make sense to select additional quorum nodes. For more information, see Labels and annotations.