administration-guide.rst: add section "Proxmox VE integration"

docs/administration-guide.rst

@@ -853,6 +853,41 @@ unused data blocks are removed.
 `Proxmox VE`_ integration
 -------------------------
 
+You need to define a new storage with type 'pbs' on your `Proxmox VE`_
+node. The following example uses ``store2`` as storage name, and
+assumes the server address is ``localhost``, and you want to connect
+as ``user1@pbs``.
+
+.. code-block:: console
+
+  # pvesm add pbs store2 --server localhost --datastore store2
+  # pvesm set store2 --username user1@pbs --password <secret>
+
+If your backup server uses a self signed certificate, you need to add
+the certificate fingerprint to the configuration. You can get the
+fingerprint by running the following command on the backup server:
+
+.. code-block:: console
+
+  # proxmox-backup-manager cert  info |grep Fingerprint
+  Fingerprint (sha256): 64:d3:ff:3a:50:38:53:5a:9b:f7:50:...:ab:fe
+
+Please add that fingerprint to your configuration to establish a trust
+relationship:
+
+.. code-block:: console
+
+  # pvesm set store2 --fingerprint  64:d3:ff:3a:50:38:53:5a:9b:f7:50:...:ab:fe
+
+After that you should be able to see storage status with:
+
+.. code-block:: console
+
+  # pvesm status --storage store2
+  Name             Type     Status           Total            Used       Available        %
+  store2            pbs     active      3905109820      1336687816      2568422004   34.23%
+
+
 
 .. include:: command-line-tools.rst