docs: faq: add entries for how to do minor and major upgrades

Adapted from Proxmox VE's FAQ

Signed-off-by: Thomas Lamprecht <t.lamprecht@proxmox.com>

diff --git a/docs/faq.rst b/docs/faq.rst
index d756d07686126d1760292f11315dee38d1262c0c..90ba828864b45d75bef1e2be8be6ca205fe0d199 100644 (file)
--- a/docs/faq.rst
+++ b/docs/faq.rst
@@ -34,6 +34,44 @@ How long will my Proxmox Backup Server version be supported?
 |Proxmox Backup 1.x     | Debian 10 (Buster)   | 2020-11       | 2022-08    | 2022-07            |
 +-----------------------+----------------------+---------------+------------+--------------------+
 
+How can I upgrade Proxmox Backup Server to the next point release?
+------------------------------------------------------------------
+
+Minor version upgrades, for example upgrading from Proxmox Backup Server in
+version 3.1 to 3.2 or 3.3, can be done just like any normal update.
+But, you should still check the `release notes
+<https://pbs.proxmox.com/wiki/index.php/Roadmap>`_ for any relevant noteable,
+or breaking change.
+
+For the update itself use either the Web UI *Node -> Updates* panel or
+through the CLI with:
+
+.. code-block:: console
+
+  apt update
+  apt full-upgrade
+
+.. note:: Always ensure you correctly setup the
+   :ref:`package repositories <sysadmin_package_repositories>` and only
+   continue with the actual upgrade if `apt update` did not hit any error.
+
+.. _faq-upgrade-major:
+
+How can I upgrade Proxmox Backup Server to the next major release?
+------------------------------------------------------------------
+
+Major version upgrades, for example going from Proxmox Backup Server 2.4 to
+3.1, are also supported.
+They must be carefully planned and tested and should **never** be started
+without having an off-site copy of the important backups, e.g., via remote sync
+or tape, ready.
+
+Although the specific upgrade steps depend on your respective setup, we provide
+general instructions and advice of how a upgrade should be performed:
+
+* `Upgrade from Proxmox Backup Server 2 to 3 <https://pbs.proxmox.com/wiki/index.php/Upgrade_from_2_to_3>`_
+
+* `Upgrade from Proxmox Backup Server 1 to 2 <https://pbs.proxmox.com/wiki/index.php/Upgrade_from_1.1_to_2.x>`_
 
 Can I copy or synchronize my datastore to another location?
 -----------------------------------------------------------