For OSDOCS-12997

Author: bjahagir-OpenShift

modules/installation-two-node-cluster-min-resource-reqs.adoc

@@ -13,6 +13,7 @@ Each cluster machine must meet the following minimum requirements:
 | Machine | Operating System | CPU ^[1]^ | RAM | Storage | Input/Output Per Second (IOPS) ^[1]^
 | Bootstrap | RHCOS | 4 | 16 GB | 120 GB | 300
 | Control plane |RHCOS | 4 | 16 GB | 120 GB | 300
+|Two-Node with Fencing (TNF)|RHCOS | 4 | 16 GB | 120 GB | 300
 
 |===
 

modules/installing-ocp-agent-ZTP.adoc

@@ -17,6 +17,12 @@ See "Challenges of the network far edge" to learn more about {ztp-first}.
 If you chose to configure the `install-config.yaml` and `agent-config.yaml` files, the configurations will be imported to the ZTP cluster manifests when they are generated.
 ====
 
+[IMPORTANT]
+====
+Zero Touch Provisioning (ZTP) is not supported for two-node clusters with fencing (TNF). Although you can use Red Hat Advanced Cluster Management (RHACM) for installations, the additional infrastructure components required for ZTP are not validated for this topology.
+
+====
+
 .Prerequisites
 
 * You have placed the `openshift-install` binary in a directory that is on your `PATH`.

modules/understanding-agent-install.adoc

@@ -60,6 +60,7 @@ Recommended cluster resources for the following topologies:
 |Single-node cluster|1|0|8 vCPUs|16 GB of RAM| 120 GB
 |Compact cluster|3|0 or 1|8 vCPUs|16 GB of RAM|120 GB
 |HA cluster|3 to 5|2 and above |8 vCPUs|16 GB of RAM|120 GB
+|Two-Node with Fencing (TNF)|2|0|4 vCPUs|16 GB of RAM|120 GB
 |====
 
 // These supported platforms are also documented in nodes/nodes/nodes-nodes-adding-node-iso.adoc and installation-configuration-parameters.adoc
@@ -72,14 +73,20 @@ In the `install-config.yaml`, specify the platform on which to perform the insta
 * `external`
 * `none`
 +
-[IMPORTANT]
-====
+
+For Two-Node with Fencing (TNF), only the following platforms are supported:
+- baremetal
+- external
+- none
+
+The `vsphere` and `nutanix` platforms are not supported for two-node clusters with fencing.
+
 For platform `none`:
 
 * The `none` option requires the provision of DNS name resolution and load balancing infrastructure in your cluster. See _Requirements for a cluster using the platform "none" option_ in the "Additional resources" section for more information.
 
 * Review the information in the link:https://access.redhat.com/articles/4207611[guidelines for deploying {product-title} on non-tested platforms] before you attempt to install an {product-title} cluster in virtualized or cloud environments.
-====
+
 +
 [NOTE]
 ====

modules/validations-before-agent-iso-creation.adoc

@@ -6,31 +6,39 @@
 [id="validations-before-agent-iso-creation_{context}"]
 = Validation checks before agent ISO creation
 
-The Agent-based Installer performs validation checks on user defined YAML files before the ISO is created. Once the validations are successful, the agent ISO
-is created.
+The Agent-based Installer validates user-defined YAML files before creating the ISO. The installer creates the agent ISO only after these validations succeed.
 
-.`install-config.yaml`
+The Agent-based Installer performs the following validation checks for Two-Node with Fencing (TNF) cluster:
 
-* `baremetal`, `vsphere` and `none` platforms are supported.
-* The `networkType` parameter must be `OVNKubernetes` in the case of `none` platform.
-* `apiVIPs` and `ingressVIPs` parameters must be set for bare metal and vSphere platforms.
-* Some host-specific fields in the bare metal platform configuration that have equivalents in `agent-config.yaml` file are ignored. A warning message is logged if these fields are set.
+* When `controlPlane.replicas` parameter is set to 2, you must provide exactly 2 fencing credentials.
+* Each fencing credential must include `hostName`, `address`, `username`, and `password`.
+* The `address` field must contain a Redfish URL, that is, the string must contain "redfish". IPMI addresses are explicitly rejected.
+* All `hostName` values must be unique.
+* If you specify `certificateVerification`, the value must be either `Enabled` or `Disabled`.
+* Fencing credentials are valid only with `baremetal`, `external`, or `none` platforms. Other platforms result in a validation error.
 
+.`install-config.yaml` validations
 
-.`agent-config.yaml`
+* The `baremetal`, `vsphere`, and `none` platforms are supported.
+* The `networkType` parameter must be `OVNKubernetes` for the `none` platform.
+* You must set the `apiVIPs` and `ingressVIPs` parameters for bare-metal and vSphere platforms.
+* Some host-specific fields in the bare-metal platform configuration that have equivalents in `agent-config.yaml` file are ignored. 
+* The installation program logs a warning message if you set these fields.
 
-* Each interface must have a defined MAC address. Additionally, all interfaces must have a different MAC address.
-* At least one interface must be defined for each host.
+.`agent-config.yaml` validations
+
+* Each interface must have a unique MAC address.
+* You must define at least one interface for each host.
 * World Wide Name (WWN) vendor extensions are not supported in root device hints.
-* The `role` parameter in the `host` object must have a value of either `master` or `worker`.
+* The `role` parameter in the `host` object must be either `master` or `worker`.
 
 [id="agent-validations-ztp_{context}"]
 == ZTP manifests
 
-.`agent-cluster-install.yaml`
+.`agent-cluster-install.yaml` validations
 
-* For IPv6, the only supported value for the `networkType` parameter is `OVNKubernetes`. The `OpenshiftSDN` value can be used only for IPv4.
+* For IPv6, the only supported value for the `networkType` parameter is `OVNKubernetes`. Use the `OpenshiftSDN` value only for IPv4.
 
-.`cluster-image-set.yaml`
+.`cluster-image-set.yaml` validations
 
 * The `ReleaseImage` parameter must match the release defined in the installer.