---
title: Creating a compute machine set on Nutanix
---

# Creating a compute machine set on Nutanix {#creating-machineset-nutanix}

You can create a different compute machine set to serve a specific purpose in your OpenShift Container Platform cluster on Nutanix. For example, you might create infrastructure machine sets and related machines so that you can move supporting workloads to the new machines, which helps ensure efficient resource allocation.

> [!IMPORTANT]
> You can use the advanced machine management and scaling capabilities only in clusters where the Machine API is operational. Clusters with user-provisioned infrastructure require additional validation and configuration to use the Machine API.
>
> Clusters with the infrastructure platform type `none` cannot use the Machine API. This limitation applies even if the compute machines that are attached to the cluster are installed on a platform that supports the feature. This parameter cannot be changed after installation.
>
> To view the platform type for your cluster, run the following command:
>
> ```terminal
> $ oc get infrastructure cluster -o jsonpath='{.status.platform}'
> ```

## Sample YAML for a compute machine set custom resource on Nutanix {#machineset-yaml-nutanix_creating-machineset-nutanix}

You can use a YAML file to automate node provisioning and ensure workloads are scheduled correctly based on role and infrastructure requirements.

The sample YAML shows how to define a Nutanix compute MachineSet for your cluster. It explains how to configure roles, labels, sizing, networking, and boot settings so new nodes are created consistently.

The sample YAML defines a Nutanix compute machine set that creates nodes that are labeled with `node-role.kubernetes.io/<role>: ""`.

In the sample, `<infrastructure_id>` is the infrastructure ID label that is based on the cluster ID that you set when you provisioned the cluster, and `<role>` is the node label to add.

### Values obtained by using the OpenShift CLI {#machineset-yaml-nutanix-oc_creating-machineset-nutanix}

In the following example, you can obtain some of the values for your cluster by using the OpenShift CLI (`oc`).

Infrastructure ID
:   The `<infrastructure_id>` string is the infrastructure ID that is based on the cluster ID that you set when you provisioned the cluster. If you have the OpenShift CLI installed, you can obtain the infrastructure ID by running the following command:

    ```terminal
    $ oc get -o jsonpath='{.status.infrastructureName}{"\n"}' infrastructure cluster
    ```

    ```yaml
    apiVersion: machine.openshift.io/v1beta1
    kind: MachineSet
    metadata:
      labels:
        machine.openshift.io/cluster-api-cluster: <infrastructure_id>
        machine.openshift.io/cluster-api-machine-role: <role>
        machine.openshift.io/cluster-api-machine-type: <role>
      name: <infrastructure_id>-<role>-<zone>
      namespace: openshift-machine-api
      annotations:
        machine.openshift.io/memoryMb: "16384"
        machine.openshift.io/vCPU: "4"
    spec:
      replicas: 3
      selector:
        matchLabels:
          machine.openshift.io/cluster-api-cluster: <infrastructure_id>
          machine.openshift.io/cluster-api-machineset: <infrastructure_id>-<role>-<zone>
      template:
        metadata:
          labels:
            machine.openshift.io/cluster-api-cluster: <infrastructure_id>
            machine.openshift.io/cluster-api-machine-role: <role>
            machine.openshift.io/cluster-api-machine-type: <role>
            machine.openshift.io/cluster-api-machineset: <infrastructure_id>-<role>-<zone>
        spec:
          metadata:
            labels:
              node-role.kubernetes.io/<role>: ""
          providerSpec:
            value:
              apiVersion: machine.openshift.io/v1
              bootType: ""
              categories:
              - key: <category_name>
                value: <category_value>
              cluster:
                type: uuid
                uuid: <cluster_uuid>
              credentialsSecret:
                name: nutanix-credentials
              image:
                name: <infrastructure_id>-rhcos
                type: name
              kind: NutanixMachineProviderConfig
              memorySize: 16Gi
              project:
                type: name
                name: <project_name>
              subnets:
              - type: uuid
                uuid: <subnet_uuid>
              systemDiskSize: 120Gi
              userDataSecret:
                name: <user_data_secret>
              vcpuSockets: 4
              vcpusPerSocket: 1
    ```

    where:

`<infrastructure_id>`
:   Specifies the infrastructure ID that is based on the cluster ID that you set when you provisioned the cluster.

`<role>`
:   Specifies the node label to add.

`<infrastructure_id>-<infra>-<region>`
:   Specifies the infrastructure ID, node label, and zone.

`annotations`
:   Specifies annotations for the cluster autoscaler.

`bootType`
:   Specifies the boot type that the compute machines use. For more information about boot types, see [Understanding UEFI, Secure Boot, and TPM in the Virtualized Environment](https://portal.nutanix.com/page/documents/kbs/details?targetId=kA07V000000H3K9SAK). Valid values are `Legacy`, `SecureBoot`, or `UEFI`. The default is `Legacy`.

    > [!NOTE]
    > You must use the `Legacy` boot type in OpenShift Container Platform 4.22.

`<categories>`
:   Specifies one or more Nutanix Prism categories to apply to compute machines. This stanza requires `key` and `value` parameters for a category key-value pair that exists in Prism Central. For more information about categories, see [Category management](https://portal.nutanix.com/page/documents/details?targetId=Prism-Central-Guide-vpc_2022_6:ssp-ssp-categories-manage-pc-c.html).

`<cluster>`
:   Specifies a Nutanix Prism Element cluster configuration. In this example, the cluster type is `uuid`, so there is a `uuid` stanza.

`<infrastructure_id>-rhcos`
:   Specifies the image to use as a boot image for your nodes. You should use the use the latest image when adding a new machine set.

`16Gi`
:   Specifies the amount of memory for the cluster in Gi.

`project`
:   Specifies the Nutanix project that you use for your cluster. In this example, the project type is `name`, so there is a `name` stanza.

`subnets`
:   Specifies one or more UUID for the Prism Element subnet object. The CIDR IP address prefix for one of the specified subnets must contain the virtual IP addresses that the OpenShift Container Platform cluster uses. A maximum of 32 subnets for each Prism Element failure domain in the cluster is supported. All subnet UUID values must be unique.

`120Gi`
:   Specifies the size of the system disk in Gi.

`<user_data_secret>`
:   Specifies the name of the secret in the user data YAML file that is in the `openshift-machine-api` namespace. Use the value that installation program populates in the default compute machine set.

`4`
:   Specifies the number of vCPU sockets.

`1`
:   Specifies the number of vCPUs per socket.

**Additional resources**
{._additional-resources}

- [Manually updating the boot image](/openshift-docs-markdown/machine_configuration/mco-update-boot-images-manual#mco-update-boot-images-manual)

## Creating a compute machine set {#machineset-creating_creating-machineset-nutanix}

To dynamically manage machine compute resources, you can create your own compute machine sets in addition to the compute machine sets created by the installation program. Use the OpenShift Container Platform CLI to automate node provisioning.

**Prerequisites**

- Deploy an OpenShift Container Platform cluster.
- Install the OpenShift CLI (`oc`).
- Log in to `oc` as a user with `cluster-admin` permission.

**Procedure**

1. Create a new YAML file that contains the compute machine set custom resource (CR) sample and is named `<file_name>.yaml`.

   Ensure that you set the `<clusterID>` and `<role>` parameter values.
2. Optional: If you are not sure which value to set for a specific field, you can check an existing compute machine set from your cluster.

   1. To list the compute machine sets in your cluster, run the following command:

      ```terminal
      $ oc get machinesets -n openshift-machine-api
      ```

      The following is example output:

      ```terminal
      NAME                                DESIRED   CURRENT   READY   AVAILABLE   AGE
      agl030519-vplxk-worker-us-east-1a   1         1         1       1           55m
      agl030519-vplxk-worker-us-east-1b   1         1         1       1           55m
      agl030519-vplxk-worker-us-east-1c   1         1         1       1           55m
      agl030519-vplxk-worker-us-east-1d   0         0                             55m
      agl030519-vplxk-worker-us-east-1e   0         0                             55m
      agl030519-vplxk-worker-us-east-1f   0         0                             55m
      ```
   2. To view values of a specific compute machine set custom resource (CR), run the following command:

      ```terminal
      $ oc get machineset <machineset_name> \
        -n openshift-machine-api -o yaml
      ```

      The following is example output:

      ```yaml
      apiVersion: machine.openshift.io/v1beta1
      kind: MachineSet
      metadata:
        labels:
          machine.openshift.io/cluster-api-cluster: <infrastructure_id>
        name: <infrastructure_id>-<role>
        namespace: openshift-machine-api
      spec:
        replicas: 1
        selector:
          matchLabels:
            machine.openshift.io/cluster-api-cluster: <infrastructure_id>
            machine.openshift.io/cluster-api-machineset: <infrastructure_id>-<role>
        template:
          metadata:
            labels:
              machine.openshift.io/cluster-api-cluster: <infrastructure_id>
              machine.openshift.io/cluster-api-machine-role: <role>
              machine.openshift.io/cluster-api-machine-type: <role>
              machine.openshift.io/cluster-api-machineset: <infrastructure_id>-<role>
          spec:
            providerSpec:
              ...
      ```

      where:

      `metadata.labels.machine.openshift.io/cluster-api-cluster`
      :   Specifies the cluster infrastructure ID.

      `metadata.labels.name`
      :   Specifies a default node label.

      > [!NOTE]
      > For clusters that have user-provisioned infrastructure, a compute machine set can only create `worker` and `infra` type machines.

      `spec.template.metadata.spec.providerSpec`
      :   Specifies the values of the compute machine set CR. The values are platform-specific. For more information about `<providerSpec>` parameters in the CR, see the sample compute machine set CR configuration for your provider.
3. Create a `MachineSet` CR by running the following command:

   ```terminal
   $ oc create -f <file_name>.yaml
   ```

**Verification**

- View the list of compute machine sets by running the following command:

  ```terminal
  $ oc get machineset -n openshift-machine-api
  ```

  The following is example output:

  ```terminal

  NAME                                DESIRED   CURRENT   READY   AVAILABLE   AGE
  agl030519-vplxk-infra-us-east-1a    1         1         1       1           11m
  agl030519-vplxk-worker-us-east-1a   1         1         1       1           55m
  agl030519-vplxk-worker-us-east-1b   1         1         1       1           55m
  agl030519-vplxk-worker-us-east-1c   1         1         1       1           55m
  agl030519-vplxk-worker-us-east-1d   0         0                             55m
  agl030519-vplxk-worker-us-east-1e   0         0                             55m
  agl030519-vplxk-worker-us-east-1f   0         0                             55m
  ```

  When the new compute machine set is available, the `DESIRED` and `CURRENT` values match. If the compute machine set is not available, wait a few minutes and run the command again.

## Labeling GPU machine sets for the cluster autoscaler {#machineset-label-gpu-autoscaler_creating-machineset-nutanix}

Label your machine sets to indicate which machines the cluster autoscaler can use for GPU-enabled nodes. Applying the accelerator label helps ensure that the autoscaler deploys the correct resources for your GPU workloads.

**Prerequisites**

- Your cluster uses a cluster autoscaler.

**Procedure**

- On the machine set that you want to create machines for the cluster autoscaler to use to deploy GPU-enabled nodes, add a `cluster-api/accelerator` label:

  ```yaml
  apiVersion: machine.openshift.io/v1beta1
  kind: MachineSet
  metadata:
    name: machine-set-name
  spec:
    template:
      spec:
        metadata:
          labels:
            cluster-api/accelerator: <accelerator_name>
  ```

  where:

  `<accelerator_name>`
  :   Specifies a label of your choice that consists of alphanumeric characters, `-`, `_`, or `.` and starts and ends with an alphanumeric character. For example, you might use `nvidia-t4` to represent Nvidia T4 GPUs, or `nvidia-a10g` for A10G GPUs.

      > [!NOTE]
      > You must specify the value of this label for the `spec.resourceLimits.gpus.type` parameter in your `ClusterAutoscaler` CR. For more information, see "Cluster autoscaler resource definition".

## Failure domains for Nutanix clusters {#mapi-failure-domain-nutanix_creating-machineset-nutanix}

To modify failure domain configurations on a Nutanix cluster, you must modify the cluster infrastructure, control plane machine set, and compute machine set custom resources (CRs) to apply the new configuration.

To add or update the failure domain configuration on a Nutanix cluster, you must make coordinated changes to several resources. The following actions are required:

1. Modify the cluster infrastructure custom resource (CR).
2. Modify the cluster control plane machine set CR.
3. Modify or replace the compute machine set CRs.

For more information, see "Adding failure domains to an existing Nutanix cluster".

## Improving reliability for multiple subnet configurations on Nutanix {#cpmso-ts-nutanix-multiple-subnet_creating-machineset-nutanix}

To improve reliability and avoid common networking problems with multiple subnet configurations on Nutanix, adhere to the configuration practices that minimize networking conflicts.

The following networking configuration and management practices can help your multiple subnet configuration perform more reliably:

- To avoid overlapping IP address assignments, use predefined static IP addresses in the `cloud-init` metadata.
- Tag all VMs, disks, and networks with a unique cluster ID.
- Avoid IP address conflicts by using dedicated subnets for each OpenShift Container Platform cluster:

  Nutanix uses Nutanix Acropolis Hypervisor (AHV) and Nutanix Prism networking to assign IP addresses to virtual machines (VMs). If a single subnet provides IP addresses for more than one OpenShift Container Platform cluster, AHV or Prism might assign the same IP address to a VM or pod in more than one cluster.

  To avoid this issue, use dedicated subnets for each OpenShift Container Platform cluster, even when you have more than one cluster on a single Prism Central instance. You can use the Prism UI or automation tools, such as Terraform or Ansible, to create separate IP address pools for each OpenShift Container Platform cluster.
- Ensure that each OpenShift Container Platform cluster uses distinct DNS zones and virtual IP address ranges.
- Avoid DHCP conflicts by maintaining DHCP allocations:

  If you use Nutanix to manage DHCP allocation, objects in your cluster might have duplicate leases. Duplicate leases can cause DHCP conflicts when you apply changes to the control plane machine set custom resource (CR) specification.

  To avoid this issue, regularly remove stale DHCP leases.
- Use automation tools, such as Terraform or Ansible, to isolate the infrastructure for each OpenShift Container Platform cluster.

**Additional resources**
{._additional-resources}

- [Cluster autoscaler resource definition](/openshift-docs-markdown/machine_management/applying-autoscaling#cluster-autoscaler-cr_applying-autoscaling)
- [Adding failure domains to an existing Nutanix cluster](/openshift-docs-markdown/installing/installing_nutanix/nutanix-failure-domains#nutanix-failure-domains-adding-to-existing-cluster_nutanix-failure-domains)
