IVdsSubSystem::QueryControllers method (vds.h)

[Beginning with Windows 8 and Windows Server 2012, the Virtual Disk Service COM interface is superseded by the Windows Storage Management API.]

Returns an object that enumerates the online and offline controllers managed by the subsystem.

Syntax

HRESULT QueryControllers(
  [out] IEnumVdsObject **ppEnum
);

Parameters

[out] ppEnum

The address of an IEnumVdsObject interface pointer that can be used to enumerate the controllers in the subsystem as controller objects. For more information, see Working with Enumeration Objects. Callers must release the interface and each of the controller objects when they are no longer needed by calling the IUnknown::Release method.

Return value

This method can return standard HRESULT values, such as E_INVALIDARG or E_OUTOFMEMORY, and VDS-specific return values. It can also return converted system error codes using the HRESULT_FROM_WIN32 macro. Errors can originate from VDS itself or from the underlying VDS provider that is being used. Possible return values include the following.

Return code/value Description
S_OK
Returns the enumeration of controllers. If the subsystem has no controllers, the enumeration is empty.
VDS_E_PROVIDER_CACHE_CORRUPT
0x8004241FL
This return value signals a software or communication problem inside a provider that caches information about the array. Use the IVdsHwProvider::Reenumerate method followed by the IVdsHwProvider::Refresh method to restore the cache.
VDS_E_OBJECT_DELETED
0x8004240BL
The subsystem object is no longer present.
VDS_E_OBJECT_STATUS_FAILED
0x80042431L
The subsystem is in a failed state and is unable to perform the requested operation.
VDS_E_ANOTHER_CALL_IN_PROGRESS
0x80042404L
Another operation is in progress; this operation cannot proceed until the previous operation or operations are complete.

Remarks

Use the QueryControllers method to get the number of controllers, and then count the controllers in the returned enumeration.

If the subsystem has no controllers, this method returns an empty enumeration object.

Requirements

   
Minimum supported client Windows Vista [desktop apps only]
Minimum supported server Windows Server 2003 [desktop apps only]
Target Platform Windows
Header vds.h
Library Uuid.lib

See also

IEnumVdsObject

IVdsHwProvider::Reenumerate

IVdsHwProvider::Refresh

IVdsSubSystem