(DOCSP-20183): Updates to snapshot history (#223)

* (DOCSP-20183): Updates to snapshot history

* Updates per copy review

Author: jeff-allen-mongo

source/core/wiredtiger.txt

@@ -57,10 +57,6 @@ metadata table is atomically updated to reference the new checkpoint.
 Once the new checkpoint is accessible, WiredTiger frees pages from the
 old checkpoints.
 
-Starting in MongoDB 5.0, you can use the
-:parameter:`minSnapshotHistoryWindowInSeconds` parameter to control how
-long WiredTiger keeps the snapshot history.
-
 Using WiredTiger, even without :ref:`journaling
 <storage-wiredtiger-journal>`, MongoDB can recover from the last
 checkpoint; however, to recover changes made after the last checkpoint,
@@ -70,6 +66,24 @@ run with :ref:`journaling <storage-wiredtiger-journal>`.
 
    .. include:: /includes/wiredtiger-node-nojournal.rst
 
+.. _storage-snapshot-history:
+
+Snapshot History Retention
+~~~~~~~~~~~~~~~~~~~~~~~~~~
+
+Starting in MongoDB 5.0, you can use the
+:parameter:`minSnapshotHistoryWindowInSeconds` parameter to specify how
+long WiredTiger keeps the snapshot history.
+
+Increasing the value of :parameter:`minSnapshotHistoryWindowInSeconds`
+increases disk usage, because the server must maintain the history of
+older modified values within the specified time window. The amount of
+disk space used depends on your workload, with higher volume workloads
+requiring more disk space.
+
+MongoDB maintains the snapshot history in the ``WiredTigerHS.wt`` file,
+located in your specified :setting:`~storage.dbPath`.
+
 .. _storage-wiredtiger-journal:
 
 Journal

source/reference/parameters.txt

@@ -3986,12 +3986,15 @@ Storage Parameters
    .. code-block:: javascript
 
       db.adminCommand( { setParameter: 1, minSnapshotHistoryWindowInSeconds: 600 } )
+      
+   .. note::
 
-   .. seealso::
+      Increasing the value of
+      :parameter:`minSnapshotHistoryWindowInSeconds` increases disk
+      usage. For more information, see :ref:`storage-snapshot-history`.
 
-      - Read concern :readconcern:`"snapshot"`
-      - :ref:`Snapshots and Checkpoints
-        <storage-wiredtiger-checkpoints>`
+      To modify this value for a :atlas:`MongoDB Atlas </>` cluster, you
+      must contact :atlas:`Atlas Support </support>`.
 
 .. parameter:: processUmask