Updates rollback to SDN procedure to add live migration

modules/how-the-live-migration-process-works.adoc

@@ -32,7 +32,7 @@ endif::[]
 Cluster Network Operator (CNO)::
 +
 --
-* Sets migration-related fields in the `network.operator` custom resource (CR) and waits for routable MTUs to be applied to all nodes.
+* Sets migration related fields in the `network.operator` custom resource (CR) and waits for routable MTUs to be applied to all nodes.
 * Patches the `network.operator` CR to set the migration mode to `Live` for OVN-Kubernetes and deploys the OpenShift SDN network plugin in migration mode.
 * Deploys OVN-Kubernetes with hybrid overlay enabled, ensuring that no racing conditions occur.
 * Waits for the OVN-Kubernetes deployment and updates the conditions in the status of the `network.config` CR.
@@ -43,54 +43,6 @@ Cluster Network Operator (CNO)::
 --
 |===
 
-////
-ifeval::["{context}" == "migrate-from-openshift-sdn"]
-If a rollback to OpenShift SDN is required, the following table describes the process.
-
-[IMPORTANT]
-====
-You must wait until the migration process from OpenShift SDN to OVN-Kubernetes network plugin is successful before initiating a rollback.
-====
-
-.Performing a rollback to OpenShift SDN
-[cols="1,1a",options="header"]
-|===
-
-|User-initiated steps|Migration activity
-
-|Suspend the MCO to ensure that it does not interrupt the migration.
-|The MCO stops.
-
-|
-Set the `migration` field of the `Network.operator.openshift.io` custom resource (CR) named `cluster` to `OpenShiftSDN`. Make sure the `migration` field is `null` before setting it to a value.
-|
-CNO:: Updates the status of the `Network.config.openshift.io` CR named `cluster` accordingly.
-
-|Update the `networkType` field.
-|
-CNO:: Performs the following actions:
-+
---
-* Destroys the OVN-Kubernetes control plane pods.
-* Deploys the OpenShift SDN control plane pods.
-* Updates the Multus objects to reflect the new network plugin.
---
-
-|
-Reboot each node in the cluster.
-|
-Cluster:: As nodes reboot, the cluster assigns IP addresses to pods on the OpenShift-SDN network.
-
-|
-Enable the MCO after all nodes in the cluster reboot.
-|
-MCO:: Rolls out an update to the systemd configuration necessary for OpenShift SDN; the MCO updates a single machine per pool at a time by default, so the total time the migration takes increases with the size of the cluster.
-
-|===
-endif::[]
-
-////
-
 ifdef::sdn[]
 :!sdn:
 endif::[]

modules/nw-network-plugin-migration-process.adoc

@@ -48,53 +48,6 @@ Cluster:: As nodes reboot, the cluster assigns IP addresses to pods on the {sdn}
 
 |===
 
-////
-ifeval::["{context}" == "migrate-from-openshift-sdn"]
-If a rollback to OpenShift SDN is required, the following table describes the process.
-
-[IMPORTANT]
-====
-You must wait until the migration process from OpenShift SDN to OVN-Kubernetes network plugin is successful before initiating a rollback.
-====
-
-.Performing a rollback to OpenShift SDN
-[cols="1,1a",options="header"]
-|===
-
-|User-initiated steps|Migration activity
-
-|Suspend the MCO to ensure that it does not interrupt the migration.
-|The MCO stops.
-
-|
-Set the `migration` field of the `Network.operator.openshift.io` custom resource (CR) named `cluster` to `OpenShiftSDN`. Make sure the `migration` field is `null` before setting it to a value.
-|
-CNO:: Updates the status of the `Network.config.openshift.io` CR named `cluster` accordingly.
-
-|Update the `networkType` field.
-|
-CNO:: Performs the following actions:
-+
---
-* Destroys the OVN-Kubernetes control plane pods.
-* Deploys the OpenShift SDN control plane pods.
-* Updates the Multus objects to reflect the new network plugin.
---
-
-|
-Reboot each node in the cluster.
-|
-Cluster:: As nodes reboot, the cluster assigns IP addresses to pods on the OpenShift-SDN network.
-
-|
-Enable the MCO after all nodes in the cluster reboot.
-|
-MCO:: Rolls out an update to the systemd configuration necessary for OpenShift SDN; the MCO updates a single machine per pool at a time by default, so the total time the migration takes increases with the size of the cluster.
-
-|===
-endif::[]
-////
-
 ifdef::sdn[]
 :!sdn:
 endif::[]

modules/nw-ovn-kubernetes-rollback-live.adoc

@@ -0,0 +1,79 @@
+// Module included in the following assemblies:
+//
+// * networking/ovn_kubernetes_network_provider/rollback-to-openshift-sdn.adoc
+
+:_mod-docs-content-type: PROCEDURE
+[id="nw-ovn-kubernetes-rollback-live_{context}"]
+= Using the live migration method to roll back to the OpenShift SDN network plugin
+
+As a cluster administrator, you can roll back to the OpenShift SDN Container Network Interface (CNI) network plugin by using the live migration method. During the migration with this method, nodes are automatically rebooted and service to the cluster is not interrupted.
+
+[IMPORTANT]
+====
+You must wait until the migration process from OpenShift SDN to OVN-Kubernetes network plugin is successful before initiating a rollback.
+====
+
+If a rollback to OpenShift SDN is required, the following table describes the process.
+
+.Performing a rollback to OpenShift SDN
+[cols="1,1a",options="header"]
+|===
+
+|User-initiated steps|Migration activity
+ifdef::openshift-rosa,openshift-dedicated[]
+| Add the `unsupported-red-hat-internal-testing` annotation to the cluster-level network configuration. 
+| The Cluster Network Operator (CNO) acknowledges the unsupported testing environment.
+endif::[]
+
+| Patch the cluster-level networking configuration by changing the `networkType` from `OVNKubernetes` to `OpenShiftSDN`.
+| 
+Cluster Network Operator (CNO):: Performs the following actions:
++
+--
+* Sets migration related fields in the `network.operator` custom resource (CR) and waits for routable MTUs to be applied to all nodes by the Machine Config Operator (MCO).
+* Patches the `network.operator` CR to set the migration mode to `Live` for OpenShiftSDN and deploys the OpenShiftSDN network plugin in migration mode.
+* Deploys OVN-Kubernetes with hybrid overlay enabled.
+* Waits for both CNI plugins to be deployed and updates the conditions in the status of the `network.config` CR.
+* Triggers the MCO to apply the new machine config to each machine config pool, which includes node cordoning, draining, and rebooting.
+* Removes migration-related fields from the `network.operator` CR and performs cleanup actions, such as deleting OpenShift SDN resources and redeploying OVN-Kubernetes in normal mode with the necessary configurations.
+* Waits for the OpenShiftSDN redeployment and updates the status conditions in the `network.config` CR to indicate migration completion. 
+--
+
+|===
+
+.Prerequisites
+
+* The {oc-first} is installed.
+* Access to the cluster as a user with the cluster-admin role is available.
+* The cluster is installed on infrastructure configured with the OVN-Kubernetes network plugin.
+* A recent backup of the etcd database is available.
+* A manual reboot can be triggered for each node.
+* The cluster is in a known good state, without any errors.
+
+.Procedure
+
+. To initiate the rollback to OpenShift SDN, enter the following command:
++
+[source,terminal]
+----
+$ oc patch Network.config.openshift.io cluster --type='merge' --patch '{"metadata":{"annotations":{"network.openshift.io/network-type-migration":""}},"spec":{"networkType":"OpenShiftSDN"}}'
+----
+
+. To watch the progress of your migration, enter the following command:
++
+[source,terminal]
+----
+$ watch -n1 'oc get network.config/cluster -o json | jq ".status.conditions[]|\"\\(.type) \\(.status) \\(.reason) \\(.message)\""  -r | column --table --table-columns NAME,STATUS,REASON,MESSAGE --table-columns-limit 4; echo; oc get mcp -o wide; echo; oc get node -o "custom-columns=NAME:metadata.name,STATE:metadata.annotations.machineconfiguration\\.openshift\\.io/state,DESIRED:metadata.annotations.machineconfiguration\\.openshift\\.io/desiredConfig,CURRENT:metadata.annotations.machineconfiguration\\.openshift\\.io/currentConfig,REASON:metadata.annotations.machineconfiguration\\.openshift\\.io/reason"'
+----
++
+The command prints the following information every second:
++
+* The conditions on the status of the `network.config.openshift.io/cluster` object, reporting the progress of the migration.
+* The status of different nodes with respect to the `machine-config-operator` resource, including whether they are upgrading or have been upgraded, as well as their current and desired configurations.
+
+. After the rollback procedure has completed, enter the following command to remove the `network.openshift.io/network-type-migration=` annotation from the `network.config` custom resource:
++
+[source,terminal]
+----
+$ oc annotate network.config cluster network.openshift.io/network-type-migration-
+----

modules/nw-ovn-kubernetes-rollback.adoc

@@ -6,25 +6,60 @@
 // This procedure applies to both a roll back and a migration
 :_mod-docs-content-type: PROCEDURE
 [id="nw-ovn-kubernetes-rollback_{context}"]
-= Migrating to the OpenShift SDN network plugin
+= Using the offline migration method to roll back to the OpenShift SDN network plugin
 
-As a cluster administrator, you can migrate to the OpenShift SDN Container Network Interface (CNI) network plugin.
-During the migration you must reboot every node in your cluster.
+As a cluster administrator, you can roll back to the OpenShift SDN Container Network Interface (CNI) network plugin by using the offline migration method. During the migration you must manually reboot every node in your cluster. With the offline migration method, there is some downtime, during which your cluster is unreachable. 
 
-ifeval::["{context}" == "rollback-to-openshift-sdn"]
 [IMPORTANT]
 ====
 You must wait until the migration process from OpenShift SDN to OVN-Kubernetes network plugin is successful before initiating a rollback.
 ====
-endif::[]
+
+If a rollback to OpenShift SDN is required, the following table describes the process.
+
+.Performing a rollback to OpenShift SDN
+[cols="1,1a",options="header"]
+|===
+
+|User-initiated steps|Migration activity
+
+|Suspend the MCO to ensure that it does not interrupt the migration.
+|The MCO stops.
+
+|
+Set the `migration` field of the `Network.operator.openshift.io` custom resource (CR) named `cluster` to `OpenShiftSDN`. Make sure the `migration` field is `null` before setting it to a value.
+|
+CNO:: Updates the status of the `Network.config.openshift.io` CR named `cluster` accordingly.
+
+|Update the `networkType` field.
+|
+CNO:: Performs the following actions:
++
+--
+* Destroys the OVN-Kubernetes control plane pods.
+* Deploys the OpenShift SDN control plane pods.
+* Updates the Multus objects to reflect the new network plugin.
+--
+
+|
+Reboot each node in the cluster.
+|
+Cluster:: As nodes reboot, the cluster assigns IP addresses to pods on the OpenShift-SDN network.
+
+|
+Enable the MCO after all nodes in the cluster reboot.
+|
+MCO:: Rolls out an update to the systemd configuration necessary for OpenShift SDN; the MCO updates a single machine per pool at a time by default, so the total time the migration takes increases with the size of the cluster.
+
+|===
 
 .Prerequisites
 
-* Install the OpenShift CLI (`oc`).
-* Access to the cluster as a user with the `cluster-admin` role.
-* A cluster installed on infrastructure configured with the OVN-Kubernetes network plugin.
+* The {oc-first} is installed.
+* Access to the cluster as a user with the cluster-admin role is available.
+* The cluster is installed on infrastructure configured with the OVN-Kubernetes network plugin.
 * A recent backup of the etcd database is available.
-* A reboot can be triggered manually for each node.
+* A manual reboot can be triggered for each node.
 * The cluster is in a known good state, without any errors.
 
 .Procedure

networking/openshift_sdn/rollback-to-ovn-kubernetes.adoc

@@ -6,7 +6,7 @@ include::_attributes/common-attributes.adoc[]
 
 toc::[]
 
-As a cluster administrator, you can rollback to the OVN-Kubernetes network plugin from the OpenShift SDN network plugin if the migration to OpenShift SDN is unsuccessful.
+As a cluster administrator, you can roll back to the OVN-Kubernetes network plugin from the OpenShift SDN network plugin if the migration to OpenShift SDN is unsuccessful.
 
 include::snippets/sdn-deprecation-statement.adoc[]
 

networking/ovn_kubernetes_network_provider/rollback-to-openshift-sdn.adoc

@@ -6,8 +6,15 @@ include::_attributes/common-attributes.adoc[]
 
 toc::[]
 
-As a cluster administrator, you can rollback to the OpenShift SDN from the OVN-Kubernetes network plugin only after the migration to the OVN-Kubernetes network plugin is completed and successful.
+As a cluster administrator, you can roll back to the OpenShift SDN network plugin from the OVN-Kubernetes network plugin using either the _offline_ migration method, or the _live_ migration method. This can only be done after the migration to the OVN-Kubernetes network plugin has successfully completed.
+
+[NOTE]
+====
+* If you used the offline migration method to migrate to the OpenShift SDN network plugin from the OVN-Kubernetes network plugin, you should use the offline migration rollback method. 
+* If you used the live migration method to migrate to the OpenShift SDN network plugin from the OVN-Kubernetes network plugin, you should use the live migration rollback method.
+====
 
 include::snippets/sdn-deprecation-statement.adoc[]
 
-include::modules/nw-ovn-kubernetes-rollback.adoc[leveloffset=+1]
+include::modules/nw-ovn-kubernetes-rollback.adoc[leveloffset=+1]
+include::modules/nw-ovn-kubernetes-rollback-live.adoc[leveloffset=+1]