Add dump rollback

docs/adminguide/migration/index.rst

@@ -27,6 +27,7 @@ Updating to a newer version
 
 In this guide, we will migrate ``parsec-backend`` from version ``v2.15.0`` to ``v2.16.0``.
 
+.. _update_docker_image_tag:
 1. Update the ``parsec-backend``'s docker image tag of in docker-compose file (``parsec-server.docker.yaml``):
 
   .. code-block:: yaml
@@ -48,8 +49,29 @@ In this guide, we will migrate ``parsec-backend`` from version ``v2.15.0`` to ``
 
     docker-compose compose -f parsec-server.docker.yaml run parsec-backend migrate
 
+.. _restart_parsec_backend_container:
 3. Restart the ``parsec-backend`` container:
 
   .. code-block:: bash
 
     docker-compose compose -f parsec-server.docker.yaml restart parsec-backend
+
+Rollback to a previous version
+******************************
+
+.. warning::
+
+  **YOU WILL LOSE DATA**
+
+  Rollback is currently limited in parsec.
+  The only possible way to rollback is to use the previous database backup.
+  So you will lose the delta of backup vs current database.
+
+To roll back to a previous version, let's say we want to downgrade ``parsec-backend`` from version ``v2.16.0`` to ``v2.15.0``.
+
+1. Downgrade the ``parsec-backend``'s docker image tag in the docker-compose file (``parsec-server.docker.yaml``).
+   Like in :ref:`Update the parsec-backend tag <update_docker_image_tag>` change the tag ``v2.16.0`` to ``v2.15.0``.
+
+2. Replace the current database with the backup on the Postgres database.
+
+3. :ref:`Restart the parsec-backend container<restart_parsec_backend_container>`