Index: /trunk/src/VBox/Main/idl/VirtualBox.xidl
===================================================================
--- /trunk/src/VBox/Main/idl/VirtualBox.xidl	(revision 29480)
+++ /trunk/src/VBox/Main/idl/VirtualBox.xidl	(revision 29481)
@@ -1094,29 +1094,4 @@
     </const>
   </enum>
-
-<!--  <enum
-       name="IoBackendType"
-       uuid="2a7e16d1-4e6b-4d5d-b0c9-b9bbe6c5b2ad"
-       >
-    <desc>
-      Type of I/O backend used for the image files in a virtual machine.
-    </desc>
-    <const name="Buffered" value="1">
-      <desc>Image files will use the host cache if possible.
-        The storage controller emulation will use a dedicated I/O thread, enable the host I/O cache and
-        use synchronous file APIs on the host.
-        This type does not work with the Async I/O manager on Linux hosts.
-        This was the only option in the API before VirtualBox 3.2 and is still the default for IDE controllers.</desc>
-    </const>
-    <const name="Unbuffered" value="2">
-      <desc>Image files will not use the host cache.
-        The storage controller emulation will use asynchronous I/O APIs on the host. This makes it possible
-        to turn off the host I/O caches because it can handle unaligned access to the file.
-        This should be used on OS X and Linux hosts if a high I/O load is expected
-        or many virtual machines are running to prevent I/O cache related hangs.
-        This is new with the API of version 3.2 and is now the default for non-IDE storage controllers.</desc>
-    </const>
-  </enum>
--->
 
   <!--