Backports DOCSP-26654 to v6.0 (#2280)

Author: jmd-mongo

source/core/sharding-balancer-administration.txt

@@ -59,8 +59,8 @@ The :term:`balancer` attempts to minimize the impact by:
 
   See also :ref:`range-migration-queuing`.
 
-- Starting a balancing round **only** when the difference in the amount 
-  of data between the shard with the most data for a sharded collection 
+- Starting a balancing round only when the **difference in the amount 
+  of data** between the shard with the most data for a sharded collection 
   and the shard with the least data for that collection reaches the 
   :ref:`migration threshold <sharding-migration-thresholds>`.
 

source/includes/autosplit-no-operation.rst

@@ -1,4 +1,4 @@
-Starting in MongoDB 6.1, automatic chunk splitting is not performed. 
+Starting in MongoDB 6.0, automatic chunk splitting is not performed. 
 This is because of balancing policy improvements. Auto-splitting commands 
 still exist, but do not perform an operation. For details, see
-:ref:`release-notes-6.1-balancing-policy-changes`.
+:ref:`release-notes-6.0-balancing-policy-changes`.

source/reference/method/sh.disableAutoSplit.txt

@@ -10,6 +10,10 @@ sh.disableAutoSplit
    :depth: 1
    :class: singlecol
 
+.. note::
+
+   .. include:: /includes/autosplit-no-operation.rst
+
 Description
 -----------
 
@@ -20,9 +24,6 @@ Description
    MongoDB automatically splits chunks based on the shard key values
    the chunk represents to keep the chunks from growing too large.
 
-   Auto-splitting is enabled by default. For more
-   information on chunk splits, see :ref:`sharding-chunk-splits`.
-
    You can only run :method:`sh.disableAutoSplit()` from a
    :binary:`~bin.mongosh` session that is connected to a
    :binary:`~bin.mongos` instance. :method:`sh.disableAutoSplit()`

source/release-notes/6.0.txt

@@ -406,6 +406,25 @@ To configure the audit log, see
 Sharding
 --------
 
+.. _release-notes-6.0-balancing-policy-changes:
+
+Balancing Policy Changes
+~~~~~~~~~~~~~~~~~~~~~~~~
+
+Starting in MongoDB 6.0, data in sharded clusters is distributed based on data 
+size rather than number of chunks. As a result, you should be aware of the
+following significant changes in sharded cluster data distribution behavior:
+
+- The balancer distributes ranges of data rather than chunks. The balancing 
+  policy looks for evenness of data distribution rather than chunk distribution.
+
+- Chunks are not subject to auto-splitting. Instead, chunks are split only when
+  moved across shards. 
+
+- A chunk is now referred to as a range. 
+
+- ``moveRange`` has replaced ``moveChunk``. 
+
 Default Chunk Size Increased from 64 MB to 128 MB 
 ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~