Update disk_index.md

site/en/reference/disk_index.md

@@ -18,7 +18,7 @@ Currently, a vector field only supports one index type. Milvus automatically del
 ## Prerequisites
 
 To use DiskANN, note that
-- DiskANN is enabled by default. If you prefer in-memory index over on-disk index, you are advised to disable this feature for a better performance.
+- DiskANN is disabled by default. If you prefer in-memory index over on-disk index, you are advised to disable this feature for a better performance.
   - To disable it, you can change `queryNode.enableDisk` to `false` in your milvus configuration file.
   - To enable it again, you can set `queryNode.enableDisk` to `true`.
 - The Milvus instance runs on Ubuntu 18.04.6 or a later release.