doc/releases/octopus.rst: add missing target_size_ratio note

This note was added to PendingReleaseNotes by 9118065c4c3803f8a2c26c28c69ffc9f14ff260a
but it apparently never found its way into doc/releases/octopus.rst.

Signed-off-by: Nathan Cutler <ncutler@suse.com>

diff --git a/doc/releases/octopus.rst b/doc/releases/octopus.rst
index 9e1126c753ccae1e288f2f74db95a3e07b8924ae..9267681942c89fe975fbb44637643a3a03d9b6a2 100644 (file)
--- a/doc/releases/octopus.rst
+++ b/doc/releases/octopus.rst
@@ -650,6 +650,15 @@ Upgrade compatibility notes
   autoscaling, see :ref:`pg-autoscaler`.  Note that existing pools in
   upgraded clusters will still be set to ``warn`` by default.
 
+* The pool parameter ``target_size_ratio``, used by the pg autoscaler,
+  has changed meaning. It is now normalized across pools, rather than
+  specifying an absolute ratio. For details, see :ref:`pg-autoscaler`.
+  If you have set target size ratios on any pools, you may want to set
+  these pools to autoscale ``warn`` mode to avoid data movement during
+  the upgrade::
+
+    ceph osd pool set <pool-name> pg_autoscale_mode warn
+
 * The ``upmap_max_iterations`` config option of mgr/balancer has been
   renamed to ``upmap_max_optimizations`` to better match its behaviour.