IVdsLun::Extend method (vdshwprv.h)

Article
02/09/2023

[Beginning with Windows 8 and Windows Server 2012, the Virtual Disk Service COM interface is superseded by the Windows Storage Management API.]

Extends a LUN by a specified number of bytes.

Syntax

HRESULT Extend(
  [in]  ULONGLONG     ullNumberOfBytesToAdd,
  [in]  VDS_OBJECT_ID *pDriveIdArray,
  [in]  LONG          lNumberOfDrives,
  [out] IVdsAsync     **ppAsync
);

Parameters

[in] ullNumberOfBytesToAdd

The number of bytes by which to extend the LUN. The number of bytes is not required to be an even multiple of the block or sector size of the drives. The provider can round the number of bytes up or down to meet alignment requirements or other restrictions. In most cases, the provider rounds up, ensuring that, with rare exceptions, the LUN is extended by at least the number of bytes requested.

[in] pDriveIdArray

A pointer to an array of drive GUIDs. The provider uses these drives to extend the LUN. The drives are used in the specified sequence; the provider uses all of the extents on one drive before moving on to the next and stops when the LUN has been extended by the requested number of bytes.

Alternatively, the caller can direct the provider to select the drives automatically by passing NULL in this parameter and zero in the lNumberOfDrives parameter. Note that passing NULL is valid only if the lNumberOfDrives parameter is zero.

[in] lNumberOfDrives

The number of drives specified in the pDriveIdArray parameter. If the caller passes zero, the provider selects the drives.

[out] ppAsync

The address of an IVdsAsync interface pointer, which VDS initializes on return. Callers must release the interface. Use this interface to cancel, wait for, or query the status of the operation.

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
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 LUN object is no longer present.
VDS_E_OBJECT_STATUS_FAILED 0x80042431L	The LUN 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.
VDS_E_OBJECT_NOT_FOUND 0x80042405L	Can be returned from any method that takes a VDS_OBJECT_ID constant. This return value indicates that the identifier does not refer to an existing object.
VDS_E_NOT_SUPPORTED 0x80042400L	This operation or combination of parameters is not supported by this provider.
VDS_E_NOT_ENOUGH_SPACE 0x8004240FL	There is not enough usable space for this operation.
VDS_E_NOT_ENOUGH_DRIVE 0x80042410L	Not enough free drives are present in the subsystem to complete this operation.

Remarks

Callers can specify a list of drives for the provider to use for extending the LUN, or direct the provider to select the drives automatically.

After the LUN is extended, the caller should use the IOCTL_DISK_UPDATE_PROPERTIES control code to make the updated disk size visible on the computer to which the LUN is unmasked.

Implementers must return a pointer to the IVdsAsync interface for this method, regardless of whether the call initiates an asynchronous operation.

If the ullNumberOfBytesToAdd parameter is greater than the number of bytes available on the drives specified in the pDriveIdArray parameter, use the specified drives first and then select from whatever other drives are available. If there are not enough such drives to extend the LUN by the requested number of bytes, return an error and do not extend the LUN.

Requirements

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