DOC-12605 Update GSI Rebalance Settings

modules/manage/pages/manage-settings/general-settings.adoc

@@ -318,7 +318,10 @@ The default cleared setting has an Index Server node rebuild any newly assigned
 You cannot enable file-based rebalance when you have enabled Memory Optimized Index Storage.  
 When you select this option, Couchbase Server copies the index files from one Index Server node to another during a rebalance instead of rebuilding them. 
 See xref:learn:clusters-and-availability/rebalance.adoc#index-rebalance-methods[Index Rebalance Methods].
-
++
+You can disable this feature from the UI or via REST API. To learn about disabling this feature via REST API, see xref:rest-api:post-settings-indexes.adoc#disable-file-transfer-based-rebalance[Curl Command to Disable the File Transfer Based Rebalance]. This feature is disabled by default.
++
+WARNING: Disabling this feature slows down the Rebalance operation.
 
 [#xdcr-maximum-processes]
 === XDCR Maximum Processes

modules/rest-api/examples/post-settings-indexes.sh

@@ -1,3 +1,4 @@
+# tag::gsi-settings[]
 curl -v -X POST http://127.0.0.1:8091/settings/indexes \
 -u Administrator:password \
 -d indexerThreads=4 \
@@ -7,3 +8,8 @@ curl -v -X POST http://127.0.0.1:8091/settings/indexes \
 -d redistributeIndexes=false \
 -d numReplica=0 \
 -d enablePageBloomFilter=false
+# end::gsi-settings[]
+
+# tag::disable-ftb-rebalance[]
+curl -X POST http://<host>:8091/settings/indexes -d enableShardAffinity=false -u Administrator:<password>
+# end::disable-ftb-rebalance[]

modules/rest-api/pages/post-settings-indexes.adoc

@@ -142,7 +142,7 @@ The following example sets the global secondary index settings.
 
 [source#example-curl,bash]
 ----
-include::example$post-settings-indexes.sh[]
+include::example$post-settings-indexes.sh[gsi-settings]
 ----
 
 == Sample Response
@@ -155,3 +155,13 @@ include::example$post-settings-indexes.jsonc[]
 ----
 
 *401*:: This response code returns an empty body.
+
+[#disable-file-transfer-based-rebalance]
+== Curl Command to Disable the File Transfer Based Rebalance
+
+The following command disables the File Transfer Based Rebalance (`enableShardAffinity`) feature in the xref:manage:general-settings.adoc#file-based-index-rebalance[Advanced Index Settings].
+
+[source#example-curl,bash]
+----
+include::example$post-settings-indexes.sh[tag=disable-ftb-rebalance]
+----