Merge "[DOCS] Adding in note for pretend_min_part_hours_passed"

doc/source/developer-docs/playbooks.rst

@@ -49,6 +49,25 @@ OpenStack services:
     * Heat
     * Horizon
 
+After successful deployment, you are able to update variables in
+``/etc/openstack_deploy/user_variables.yml``.
+
+* Object Storage (swift)
+
+   - The ``pretend_min_part_hours_passed`` option can now be
+     passed to swift-ring-builder prior to performing a rebalance. This is set by
+     the ``swift_pretend_min_part_hours_passed`` boolean variable.
+     The default for this variable is False. However, we recommend using
+     ``-e swift_pretend_min_part_hours_passed=True`` when running the
+     ``os-swift.yml`` playbook to avoid resetting ``min_part_hours`` unintentionally.
+
+     .. important::
+
+        If you run this command and deploy rebalanced rings before a replication
+        pass completes, you may introduce unavailability in your cluster.
+
+        This should only be used for testing or fully rebalanced clusters.
+
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 .. include:: navigation.txt