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Selecting a larger AWS instance type for control plane machines

If the control plane machines in an Amazon Web Services (AWS) cluster require more resources, you can select a larger AWS instance type for the control plane machines to use.

The procedure for clusters that use a control plane machine set is different from the procedure for clusters that do not use a control plane machine set.

If you are uncertain about the state of the ControlPlaneMachineSet CR in your cluster, you can verify the CR status.
Additional resources

Changing the Amazon Web Services instance type by using a control plane machine set

If you need more resources for your control plane machines, you can change the Amazon Web Services (AWS) instance type that they use. To change the instance type, you update the instance type value in the control plane machine set custom resource (CR).

Prerequisites

  • You have access to the OpenShift CLI (oc) as a user with administrator privileges.

  • Your AWS cluster uses a control plane machine set.

Procedure

  1. Edit your control plane machine set CR by running the following command:

    $ oc edit controlplanemachineset.machine.openshift.io cluster --namespace openshift-machine-api

  2. Update the CR to implement your configuration changes:

    apiVersion: machine.openshift.io/v1
kind: ControlPlaneMachineSet
# ...
spec:
  template:
    machines_v1beta1_machine_openshift_io:
      spec:
        providerSpec:
          value:
            instanceType: <compatible_aws_instance_type>

    where <compatible_aws_instance_type> specifies a larger AWS instance type with the same base. For example, you can change this value from m6i.xlarge to m6i.2xlarge or m6i.4xlarge.

  3. Save your changes and exit the object specification.

    When you save an update to the control plane machine set, the Control Plane Machine Set Operator updates the control plane machines according to your configured update strategy.

    • For clusters that use the default RollingUpdate update strategy, the Operator automatically propagates the changes to your control plane configuration.

    • For clusters that are configured to use the OnDelete update strategy, you must replace your control plane machines manually.

Additional resources

Changing the Amazon Web Services instance type by using the AWS console

You can change the Amazon Web Services (AWS) instance type that your control plane machines use by updating the instance type in the AWS console.

Prerequisites

  • You have access to the AWS console with the permissions required to modify the EC2 Instance for your cluster.

  • You have access to the OKD cluster as a user with the cluster-admin role.

Procedure

  1. Open the AWS console and fetch the instances for the control plane machines.

  2. Choose one control plane machine instance.

    1. For the selected control plane machine, back up the etcd data by creating an etcd snapshot. For more information, see "Backing up etcd".

    2. In the AWS console, stop the control plane machine instance.

    3. Select the stopped instance, and click Actions → Instance Settings → Change instance type.

    4. Change the instance to a larger type, ensuring that the type is the same base as the previous selection, and apply changes. For example, you can change m6i.xlarge to m6i.2xlarge or m6i.4xlarge.

    5. Start the instance.

    6. If your OKD cluster has a corresponding Machine object for the instance, update the instance type of the object to match the instance type set in the AWS console.

  3. Repeat this process for each control plane machine.

Additional resources