Merge pull request #71747 from skopacz1/OSDOCS-3630

OSDOCS#3630: OTA etcd backup guidance

Author: opayne1

modules/update-etcd-backup.adoc

@@ -0,0 +1,23 @@
+// Module included in the following assemblies:
+//
+// * updating/preparing_for_updates/updating-cluster-prepare.adoc
+
+:_mod-docs-content-type: REFERENCE
+[id="update-etcd-backup_{context}"]
+= etcd backups before cluster updates
+
+etcd backups record the state of your cluster and all of its resource objects.
+You can use backups to attempt restoring the state of a cluster in disaster scenarios where you cannot recover a cluster in its currently dysfunctional state.
+
+In the context of updates, you can attempt an etcd restoration of the cluster if an update introduced catastrophic conditions that cannot be fixed without reverting to the previous cluster version.
+etcd restorations might be destructive and destabilizing to a running cluster, use them only as a last resort.
+
+[WARNING]
+====
+Due to their high consequences, etcd restorations are not intended to be used as a rollback solution.
+Rolling your cluster back to a previous version is not supported.
+If your update is failing to complete, contact Red{nbsp}Hat support.
+====
+
+There are several factors that affect the viability of an etcd restoration.
+For more information, see "Backing up etcd data" and "Restoring to a previous cluster state".

updating/preparing_for_updates/updating-cluster-prepare.adoc

@@ -58,6 +58,16 @@ include::modules/update-preparing-conditional.adoc[leveloffset=+1]
 .Additional resources
 * xref:../../updating/understanding_updates/how-updates-work.adoc#update-evaluate-availability_how-updates-work[Evaluation of update availability]
 
+// etcd backups before cluster updates
+include::modules/update-etcd-backup.adoc[leveloffset=+1]
+
+[role="_additional-resources"]
+.Additional resources
+
+* xref:../../backup_and_restore/control_plane_backup_and_restore/backing-up-etcd.adoc#backup-etcd[Backing up etcd]
+
+* xref:../../backup_and_restore/control_plane_backup_and_restore/disaster_recovery/scenario-2-restoring-cluster-state.adoc#dr-restoring-cluster-state[Restoring to a previous cluster state]
+
 // Best practices for cluster updates
 include::modules/update-best-practices.adoc[leveloffset=+1]