Index: /trunk/src/VBox/Main/MediumImpl.cpp
===================================================================
--- /trunk/src/VBox/Main/MediumImpl.cpp	(revision 23946)
+++ /trunk/src/VBox/Main/MediumImpl.cpp	(revision 23947)
@@ -2488,4 +2488,16 @@
 
     return rc;
+}
+
+STDMETHODIMP Medium::Resize(ULONG64 aLogicalSize, IProgress **aProgress)
+{
+    CheckComArgOutPointerValid(aProgress);
+
+    AutoCaller autoCaller(this);
+    CheckComRCReturnRC(autoCaller.rc());
+
+    NOREF(aLogicalSize);
+    NOREF(aProgress);
+    ReturnComNotImplemented();
 }
 
Index: /trunk/src/VBox/Main/idl/VirtualBox.xidl
===================================================================
--- /trunk/src/VBox/Main/idl/VirtualBox.xidl	(revision 23946)
+++ /trunk/src/VBox/Main/idl/VirtualBox.xidl	(revision 23947)
@@ -9682,4 +9682,35 @@
     </method>
 
+    <method name="resize">
+      <desc>
+        Starts resizing this medium. This means that the nominal size of the
+        medium is set to the new value. Both increasing and decreasing the
+        size is possible, and there are no safety checks, since VirtualBox
+        does not make any assumptions about the medium contents.
+
+        Resizing usually needs additional disk space, and possibly also
+        some temporary disk space. Note that resize does not create a full
+        temporary copy of the medium, so the additional disk space requirement
+        is usually much lower than using the clone operation.
+
+        This medium will be placed to <link to="MediumState_LockedWrite"/>
+        state for the duration of this operation.
+
+        Please note that the results can be either returned straight away,
+        or later as the result of the background operation via the object
+        returned via the @a progress parameter.
+
+        <result name="VBOX_E_NOT_SUPPORTED">
+          Medium format does not support resizing.
+        </result>
+      </desc>
+      <param name="logicalSize" type="unsigned long long" dir="in">
+        <desc>New nominal capacity of the medium in megabytes.</desc>
+      </param>
+      <param name="progress" type="IProgress" dir="return">
+        <desc>Progress object to track the operation completion.</desc>
+      </param>
+    </method>
+
     <method name="reset">
       <desc>
Index: /trunk/src/VBox/Main/include/MediumImpl.h
===================================================================
--- /trunk/src/VBox/Main/include/MediumImpl.h	(revision 23946)
+++ /trunk/src/VBox/Main/include/MediumImpl.h	(revision 23947)
@@ -147,4 +147,5 @@
                         IMedium *aParent, IProgress **aProgress);
     STDMETHOD(Compact)(IProgress **aProgress);
+    STDMETHOD(Resize)(ULONG64 aLogicalSize, IProgress **aProgress);
     STDMETHOD(Reset)(IProgress **aProgress);