Docs: Note feature missing from reindex
Reindex-from-remote doesn't support slices and I hadn't documented
that.
Closes
@@ -440,6 +440,10 @@ version.
To enable queries sent to older versions of Elasticsearch the `query` parameter
is sent directly to the remote host without validation or modification.
+NOTE: Reindexing from remote clusters does not support
+<<docs-reindex-manual-slice, manual>> or
+<<docs-reindex-automatic-slice, automatic slicing>>.
+
Reindexing from a remote server uses an on-heap buffer that defaults to a
maximum size of 100mb. If the remote index includes very large documents you'll
need to use a smaller batch size. The example below sets the batch size `10`
