Upgrade Guide with ISO and Template
###################################

.. _20.1.1|EKB-3853:

.. important::

   * For VOSS-4-UC release 20.1.1, refer to the VOSS-4-UC 20.1.1 Release Changes and Impact
     document for details on model and workflow changes. Customizations related to these changes may be
     affected.

   * From Release 19.2.1 onwards, the minimum RAM hardware requirements for all unified nodes is 16GB.

     Refer to the topic on Memory (RAM) Increase for Large End User Capacity in the Platform Guide
     for steps to upgrade your virtual machine.
   * When upgrading from any of the following versions, first obtain and apply the patch corresponding to your
     version from
    
     **https://voss.portalshape.com > Downloads > VOSS-4-UC > [version_number] > patches**:

     version numbers:

     * 19.1.2 - ``EKB-3853-19.1.2_patch``
     * 19.2.1 - ``EKB-3853-19.2.1_patch``
     * 19.3.1 - ``EKB-3853-19.3.1_patch``
     * 19.3.2 - ``EKB-3853-19.3.2_patch``



.. note::

   Normal operations will be interrupted during an upgrade. Carry out the upgrade in a maintenance
   window. Refer to the type of upgrade for details on the upgrade duration.

****************
Upgrade Planning
****************


.. toctree::
   :maxdepth: 2

   /src/user/operations/concepts-data-migration-upgrade
   /src/user/platform/reference-screen-command

*****************
Multinode Upgrade
*****************


.. toctree::
   :maxdepth: 2

   /src/user/install/multinode-upgrade-ISO
   
*******************
Standalone Upgrade
*******************


.. toctree::
   :maxdepth: 2

   /src/user/install/upgrade-cucdm-ISO