updating more info on how to add or remove DDS wihtout any confilicts…

docs/platform/howto/add-storage-space.rst

@@ -1,18 +1,23 @@
 Add or remove storage 
 =======================
 
-With :doc:`dynamic disk sizing <../concepts/dynamic-disk-sizing>`, you can add or remove disk storage both when you create a service and later for a running service. 
+With :doc:`dynamic disk sizing <../concepts/dynamic-disk-sizing>`, you can add or remove disk storage (by factor of 10 GiB) both when you create a service and later for a running service.
 
 .. note::
-   This feature is not available for all service plans.
+   - You cannot add or remove storage when service nodes are in the rebalancing state, for example, during a maintenance update or a service upgrade.
+   - This feature is not available for all service plans.
+
+Use Aiven console
+-----------------
 
 Add storage during new service creation
------------------------------------------
+'''''''''''''''''''''''''''''''''''''''
 
 You can add disk storage when :doc:`creating a new service <../howto/create_new_service>`. 
 
+
 Add storage to a running service
----------------------------------
+''''''''''''''''''''''''''''''''
 
 You can add storage to your running service in `Aiven Console <https://console.aiven.io/>`_ without interrupting the service. 
 
@@ -24,12 +29,12 @@ You can add storage to your running service in `Aiven Console <https://console.a
 
 #. In the **Upgrade service storage** window, use the slider to add disk storage.
 
-   ..note::
+#. Select **Save changes**.
+
+.. note::
 
       The price shown for the additional storage includes backup costs.
 
-#. Select **Save changes**.
-
 .. topic:: Result
 
    The additional storage is available for immediate use.  
@@ -39,18 +44,18 @@ You can add storage to your running service in `Aiven Console <https://console.a
    Storage optimization is performed at the next maintenance update after a change to the storage size. Due to cloud provider limitations, there is a limit on how many times storage can be increased between two maintenance updates. When this limit is reached, you need to perform a maintenance update for performance optimization. It's best to carefully plan increases to avoid reaching this limit.
 
 Remove additional storage
----------------------------
+'''''''''''''''''''''''''
 
 You can remove storage that you previously added to a service.
 
 Before you start
-''''''''''''''''
+""""""""""""""""
 
 - Make sure the data in your service does not exceed your service plan's allocated storage. If it does, you will not be able to remove the additional storage. 
 - Plan for the time it takes to recycle the nodes. The service will be in a rebalancing state after removing storage. The time it takes depends on the service. 
 
 Remove added storage
-''''''''''''''''''''
+""""""""""""""""""""
 
 #. Log in to `Aiven Console <https://console.aiven.io/>`_, and go to your project.
 
@@ -68,3 +73,18 @@ Remove added storage
 .. topic:: Result
 
    Your additional disk space has been removed. The service is in the **Rebalancing** state while the nodes are being recycled. 
+
+Use Aiven CLI
+-------------
+
+You can use :doc:`Aiven CLI </docs/tools/cli>` to add or remove additional storage by :ref:`updating the service configuration <avn-cli-service-update>` using command ``avn service update`` with flag ``--disk-space-gib``. Specify the value for the flag as the total disk space that you need for your service.
+For example, if you use a ``Startup-4`` plan with a 80-GiB disk by default and you would like to add an extra 10-GiB disk, the value that the ``--disk-space-gib`` flag requires is ``90``.
+
+.. code-block:: bash
+
+      avn service update --disk-space-gib 90 --project PROJECT_NAME SERVICE_NAME
+
+.. note::
+
+   - When you perform a service upgrade or downgrade horizontally, remember to include all additional disks the service uses. For example, when switching from ``Startup-4`` to ``Business-4`` or from ``Business-4`` to ``Startup-4``, include all the additional disks available for this service.
+   - Similarly, when you fork an existing service, include all additional disks the service uses.

docs/platform/howto/scale-services.rst

@@ -16,4 +16,5 @@ When creating a new Aiven service, you are not tied to a plan. Your services can
 
 .. note::
 
-    You can also use the :ref:`dedicated service update function <avn-cli-service-update>` to scale your service plan via the :doc:`Aiven CLI </docs/tools/cli>`.
+    - You can also use the :ref:`dedicated service update function <avn-cli-service-update>` to scale your service plan via the :doc:`Aiven CLI </docs/tools/cli>`.
+    - When you perform a service upgrade or downgrade horizontally, remember to include all additional disks the service uses. For example, when switching from ``Startup-4`` to ``Business-4`` or from ``Business-4`` to ``Startup-4``, include all the additional disks available for this service.