Merge pull request #29506 from miabbott/update_add_rhcos_machines

provide additional instructions for adding more compute machines

Author: Bob Furu

machine_management/user_infra/adding-bare-metal-compute-user-infra.adoc

@@ -12,6 +12,11 @@ You can add more compute machines to your {product-title} cluster on bare metal.
 * You xref:../../installing/installing_bare_metal/installing-bare-metal.adoc#installing-bare-metal[installed a cluster on bare metal].
 * 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_bare_metal/installing-bare-metal.adoc#installing-bare-metal[installation procedure].
 
+[IMPORTANT]
+====
+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+].
+====
+
 [id="creating-machines-bare-metal"]
 == Creating {op-system-first} machines