Added release notes and migration guide

Author: mariadb-mmontes

release-notes/enterprise-operator/25.10.md

@@ -0,0 +1,36 @@
+# MariaDB Enterprise Kubernetes Operator 25.08 LTS
+
+**Release date**: 28th October 2025
+
+We are excited to announce release of **MariaDB Enterprise Operator 25.10** - delivering enterprise-grade automation for managing MariaDB Enterprise workloads on Kubernetes and Red Hat OpenShift.
+
+If you're upgrading from previous versions, __please follow the [UPGRADE GUIDE](https://mariadb.com/docs/tools/mariadb-enterprise-operator/migrations/migrate-25.10)__ to ensure a safe transition.
+
+### Replication-based topology
+
+The operator now supports provisioning and operating MariaDB clusters using asynchronous replication as a high availability topology, providing an alternative to the existing synchronous multi-master topology based on Galera. In a replication setup, one primary server handles all write operations while one or more replica servers replicate data from the primary, being able to handle read operations. More precisely, the primary has a binary log and the replicas asynchronously replicate the binary log events over the network. 
+
+Operations and the full lifecycle of the replication cluster are fully managed by the operator, including provisioning, scaling, replica recovery and disaster recovery. For the primary failover/switchover, we recommend using MaxScale 25.10, currently supported by this version.
+
+Please refer to the [replication](https://mariadb.com/docs/tools/mariadb-enterprise-operator/topologies/replication) for more details about this topology.
+
+### LTS releases
+
+With the 25.10 release, we’re introducing annual LTS releases for the Enterprise Kubernetes Operator to provide long-term stability and a predictable upgrade path. LTS releases focus on security updates and critical bug fixes and maintain CRD compatibility within the LTS release, helping teams meet SLAs and reduce operational overhead in mission-critical environments. New features will continue to ship in the rolling releases between LTS cycles, while the LTS serves as a hardened, stable baseline.
+
+Please refer to the [OpenShift](https://mariadb.com/docs/tools/mariadb-enterprise-operator/installation/openshift#release-channels) and helm documentation to start using LTS releases.
+
+### Platform and component versions
+
+The current release has been tested with the following versions:
+
+| Platform/Component        | Version  |
+| ------------------------- | -------- |
+| Kubernetes                | 1.34     |
+| OpenShift                 | 4.18.6, 4.16.4 |
+| MariaDB Enterprise Server | 11.8.3-1 |
+| MaxScale                  | 25.10.0 |
+
+{% include "https://app.gitbook.com/s/SsmexDFPv2xG2OTyO5yV/~/reusable/pNHZQXPP5OEz2TgvhFva/" %}
+
+{% @marketo/form formid="4316" formId="4316" %}

tools/mariadb-enterprise-operator/migrations/migrate-25.10.md

@@ -0,0 +1,102 @@
+# 25.10 LTS migration guide
+
+This guide illustrates, step by step, how to migrate to `25.10.0` from previous versions. 
+
+
+- The Galera data-plane must be updated to the `25.10.0` version. 
+
+
+If you want the operator to automatically update the data-plane (i.e. init and agent containers), you can set `updateStrategy.autoUpdateDataPlane=true` in your `MariaDB` resources:
+```diff
+apiVersion: enterprise.mariadb.com/v1alpha1
+kind: MariaDB
+metadata:
+  name: mariadb-galera
+spec:
+  updateStrategy:
++   autoUpdateDataPlane: true
+```
+
+Alternatively, you can also do this manually:
+
+```diff
+apiVersion: enterprise.mariadb.com/v1alpha1
+kind: MariaDB
+metadata:
+  name: mariadb-galera
+spec:
+  galera:
+    agent:
+-      image: docker.mariadb.com/mariadb-enterprise-operator:1.0.0
++      image: docker.mariadb.com/mariadb-enterprise-operator:25.10.0
+    initContainer:
+-      image: docker.mariadb.com/mariadb-enterprise-operator:1.0.0
++      image: docker.mariadb.com/mariadb-enterprise-operator:25.10.0
+```
+
+- Then, you may proceeed to update the operator. If you are using __Helm__:
+
+Upgrade `mariadb-enterprise-operator-crds` to `25.10.0`:
+```bash
+helm repo update mariadb-enterprise-operator
+helm upgrade --install mariadb-enterprise-operator-crds  mariadb-enterprise-operator/mariadb-enterprise-operator-crds --version 25.10.0
+```
+
+Upgrade `mariadb-enterprise-operator` to `25.10.0`:
+```bash 
+helm repo update mariadb-enterprise-operator
+helm upgrade --install mariadb-enterprise-operator mariadb-enterprise-operator/mariadb-enterprise-operator --version 25.10.0 
+```
+
+- If you are on __OpenShift__:
+
+
+Update the `startingCSV` in your `Subscription` object:
+```yaml
+apiVersion: operators.coreos.com/v1alpha1
+kind: Subscription
+metadata:
+  name: mariadb-enterprise-operator
+  namespace: openshift-operators
+spec:
+  channel: stable
+  installPlanApproval: Manual
+  name: mariadb-enterprise-operator
+  source: certified-operators
+  sourceNamespace: openshift-marketplace
+  startingCSV: mariadb-enterprise-operator.v25.10.0
+``` 
+
+As part of the 25.10 LTS release, we have introduced new [release channels](https://mariadb.com/docs/tools/mariadb-enterprise-operator/installation/openshift#release-channels). Consider switching to the `stable-v25.10` if you are willing to stay in the `25.10.x` version:
+
+```yaml
+apiVersion: operators.coreos.com/v1alpha1
+kind: Subscription
+metadata:
+  name: mariadb-enterprise-operator
+  namespace: openshift-operators
+spec:
+  channel: stable-v25.10
+  installPlanApproval: Automatic
+  name: mariadb-enterprise-operator
+  source: certified-operators
+  sourceNamespace: openshift-marketplace
+``` 
+
+- If you previously set `updateStrategy.autoUpdateDataPlane=true`, you may consider reverting the changes once the upgrades have finished to avoid unexpected updates:
+
+```diff
+apiVersion: enterprise.mariadb.com/v1alpha1
+kind: MariaDB
+metadata:
+  name: mariadb-galera
+spec:
+  updateStrategy:
++   autoUpdateDataPlane: false
+-   autoUpdateDataPlane: true
+```
+
+{% include "https://app.gitbook.com/s/SsmexDFPv2xG2OTyO5yV/~/reusable/pNHZQXPP5OEz2TgvhFva/" %}
+
+
+{% @marketo/form formId="4316" %}