// Module included in the following assemblies:
//
// * machine_management/user_infra/adding-vsphere-compute-user-infra.adoc

:_mod-docs-content-type: REFERENCE
[id="adding-vsphere-compute-user-infra_{context}"]
= Prerequisites

[role="_abstract"]
There are several prerequisites that must be completed before you add more compute machines to your {product-title} cluster on VMware vSphere manually.

[NOTE]
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You can also xref:../../machine_management/creating_machinesets/creating-machineset-vsphere.adoc#creating-machineset-vsphere[use compute machine sets] to automate the creation of additional VMware vSphere compute machines for your cluster.
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The following prerequisites must be met:

* You xref:../../installing/installing_vsphere/upi/installing-vsphere.adoc#installing-vsphere[installed a cluster on vSphere].

* You have installation media and {op-system-first} images that you used to create your cluster. If you do not have these files, you must obtain them by following the instructions in the xref:../../installing/installing_vsphere/upi/installing-vsphere.adoc#installing-vsphere[installation procedure].

[IMPORTANT]
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If you do not have access to the {op-system-first} images that were used to create your cluster, you can add more compute machines to your {product-title} cluster with newer versions of {op-system-first} images. For instructions, see link:https://access.redhat.com/solutions/5514051[Adding new nodes to UPI cluster fails after upgrading to OpenShift 4.6+].
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