7.10. Required parameters for the Ansible hosts file
You must define the following parameters in the Ansible hosts file before you add Red Hat Enterprise Linux (RHEL) compute machines to your cluster.
| Paramter | Description | Values |
|---|---|---|
|
| The SSH user that allows SSH-based authentication without requiring a password. If you use SSH key-based authentication, then you must manage the key with an SSH agent. |
A user name on the system. The default value is |
|
|
If the values of |
|
|
|
Specifies a path and file name to a local directory that contains the | The path and name of the configuration file. |
7.10.1. Optional: Removing RHCOS compute machines from a cluster
After you add the Red Hat Enterprise Linux (RHEL) compute machines to your cluster, you can optionally remove the Red Hat Enterprise Linux CoreOS (RHCOS) compute machines to free up resources.
Prerequisites
- You have added RHEL compute machines to your cluster.
Procedure
View the list of machines and record the node names of the RHCOS compute machines:
$ oc get nodes -o wide
For each RHCOS compute machine, delete the node:
Mark the node as unschedulable by running the
oc adm cordoncommand:$ oc adm cordon <node_name> 1- 1
- Specify the node name of one of the RHCOS compute machines.
Drain all the pods from the node:
$ oc adm drain <node_name> --force --delete-local-data --ignore-daemonsets 1- 1
- Specify the node name of the RHCOS compute machine that you isolated.
Delete the node:
$ oc delete nodes <node_name> 1- 1
- Specify the node name of the RHCOS compute machine that you drained.
Review the list of compute machines to ensure that only the RHEL nodes remain:
$ oc get nodes -o wide
- Remove the RHCOS machines from the load balancer for your cluster’s compute machines. You can delete the virtual machines or reimage the physical hardware for the RHCOS compute machines.
