<div class="content" name="QueryUnallocatedDisks" uuid="f952f2f8-be1e-4667-ac58-f3ce845a0fb4"><p>The QueryUnallocatedDisks method enumerates the <a href="8eef5d42-22d7-4302-aed9-12face91505a#gt_caa0fa47-db36-4509-b74d-1829bcce288f" data-linktype="relative-path">unallocated disks</a> on the
server.</p><dl>
<dd>
<div><pre> HRESULT QueryUnallocatedDisks(
   [out] IEnumVdsObject** ppEnum
 );
</pre></div>
</dd></dl><p><b>ppEnum: </b>A pointer to an <a href="29084d98-40c8-4a10-a45e-4cfc0d8f8f03" data-linktype="relative-path">IEnumVdsObject</a> interface
that, if the operation is successfully completed, receives the IEnumVdsObject
interface of the object that contains an enumeration of <a href="8eef5d42-22d7-4302-aed9-12face91505a#gt_c4133b2a-a990-4042-ba44-7fda3090f118" data-linktype="relative-path">disk</a> objects that
correspond to unallocated disks on the server. Callers MUST release the
interface that is received when they are done with it.</p><p><b>Return Values: </b>The method MUST return zero or
a non-error <a href="8eef5d42-22d7-4302-aed9-12face91505a#gt_799103ab-b3cb-4eab-8c55-322821b2b235" data-linktype="relative-path">HRESULT</a> (as
specified in <a href="../ms-erref/1bc92ddf-b79e-413c-bbaa-99a5281a6c90" data-linktype="relative-path">[MS-ERREF]</a>)
to indicate success, or return an implementation-specific nonzero error code to
indicate failure. For the HRESULT values predefined by the Virtual Disk Service
Remote Protocol, see section <a href="5102cc53-3143-4268-ba4c-6ea39e999ab4" data-linktype="relative-path">2.2.3</a>.</p><p>When the server receives this message, it MUST validate the
following parameter:</p><ul><li><p><span><span> 
</span></span>Verify that <i>ppEnum</i> is not NULL.</p>
</li></ul><p>The server MUST point <i>ppEnum</i> to an IEnumVdsObject
interface that contains the enumeration of unallocated disk objects in the list
of cached storage management objects, as specified in section <a href="0d8d514a-16c5-44ae-b4bb-a333e19ea5b6" data-linktype="relative-path">3.4.1.3</a>, and return an
HRESULT indicating failure or success.</p></div>