Red Hat CoreOS is a lightweight container operating system born from merging of Project Atomic and Container Linux to become Red Hat Enterprise Linux (RHEL) CoreOS. RHEL CoreOS combines the ease of over-the-air updates from Container Linux with the Red Hat Enterprise Linux kernel to deliver a more secure, easily managed container host. RHEL CoreOS is the recommended operating system for all workloads in Red Hat OpenShift container platform.

In this guide we will be importing RHCOS OVA OS template to VMware vSphere environment using vCenter console. If your Red Hat OpenShift installation is not over vCenter, the same can be done directly on ESXI node console. Just follow the steps in the following sections and by the end you’ll have a RHCOS OVA template added to VMware environment.

Download RHCOS OVA image from OpenShift 4 rhcos dependencies download URL.

Save the OVA image in a directory that you can access from your local system.

Launch VMware vCenter console, then select a directory in your cluster where you want to place the template. Right click and choose “Deploy OVF Template”.

Choose “Local file” in the next page

Browse downloads directory and choose downloaded “rhcos” vmware ova file.

Give VM template a name, and select location for the virtual machine

Select a compute resource

Review provided details if correct. Some settings can be changed once the template is created.

Select storage for disk files in the next screen.

Select network used by OpenShift virtual machines

Customize some parameters here or skip and do later

With all the settings provided proceed to deploy the template.

You should be able to see progress as upload begins.

The instance created will be powered off. Please don’t start it.

Customize VM Options under VM > Actions > Edit Settings > VM Options > EDIT CONFIGURATION

Under Configuration Parameters click “ADD CONFIGURATIOn PARAMS“.

Add below three parameters:

VM optionsValue
guestinfo.ignition.config.datachageme
guestinfo.ignition.config.data.encodingbase64
disk.EnableUUIDTRUE

See below screenshot

From here you can follow VMware UPI or IPI installation guides to deploy OpenShift cluster in a VMware vSphere environment.

Other guides on OpenShift:

Extend root filesystem /sysroot on OpenShift CoreOS (RHCOS)

Run CentOS Container Pod in Kubernetes | OpenShift