nodes-nodes-working-master-schedulable.adoc

Configuring master nodes as schedulable

As of {product-title} 4.2, you can configure master nodes to be schedulable, meaning that new Pods are allowed for placement on the master nodes. By default, master nodes are not schedulable. However, if your cluster does not contain any worker nodes, then master nodes are marked schedulable by default.

Important

In version {product-version}, the ability to create a cluster that does not have worker nodes is available to only clusters that are deployed on bare metal as a technology preview. For all other cluster types, you can set the masters to be schedulable but must retain worker nodes.

You can allow or disallow master nodes to be schedulable by configuring the mastersSchedulable field.

Procedure

1. Edit the schedulers.config.openshift.io resource.

   $ oc edit schedulers.config.openshift.io cluster

2. Configure the mastersSchedulable field.

   apiVersion: config.openshift.io/v1
   kind: Scheduler
   metadata:
     creationTimestamp: "2019-09-10T03:04:05Z"
     generation: 1
     name: cluster
     resourceVersion: "433"
     selfLink: /apis/config.openshift.io/v1/schedulers/cluster
     uid: a636d30a-d377-11e9-88d4-0a60097bee62
   spec:
     mastersSchedulable: false (1)
     policy:
       name: ""
   status: {}

   1. Set to true to allow master nodes to be schedulable, or false to disallow master nodes to be schedulable.

3. Save the file to apply the changes.