Partitions a disk as specified by drive layout and partition information data.

To perform this operation, call the DeviceIoControl function with the parameters specified below.

IOCTL_DISK_SET_DRIVE_LAYOUT has been superseded by IOCTL_DISK_SET_DRIVE_LAYOUT_EX, which retrieves layout information for AT and EFI (Extensible Firmware Interface) partitions.

BOOL DeviceIoControl(
  (HANDLE) hDevice,            // handle to device
  (LPVOID) lpInBuffer,         // input buffer 
  (DWORD) nInBufferSize,       // size of input buffer 
  NULL,                        // lpOutBuffer
  0,                           // nOutBufferSize
  (LPDWORD) lpBytesReturned,   // number of bytes returned
  (LPOVERLAPPED) lpOverlapped  // OVERLAPPED structure



A handle to the disk drive to be partitioned. To obtain a device handle, call the CreateFile function.


The control code for the operation. Use IOCTL_DISK_SET_DRIVE_LAYOUT for this operation.


A pointer to a buffer that contains drive layout and partition information data. The data exists as a DRIVE_LAYOUT_INFORMATION data structure and a series of PARTITION_INFORMATION data structures, one of the latter for each proposed partition on the drive.


The size of the input buffer, in bytes. Must be large enough to contain one DRIVE_LAYOUT_INFORMATION data structure and as many PARTITION_INFORMATION data structures as there are proposed partitions on the drive.


Not used with this operation; set to NULL.


Not used with this operation; set to zero.


A pointer to a variable that receives the size of the data stored in the output buffer, in bytes.

If lpOverlapped is NULL, lpBytesReturned cannot be NULL. Even when an operation returns no output data and lpOutBuffer is NULL, DeviceIoControl makes use of lpBytesReturned. After such an operation, the value of lpBytesReturned is meaningless.

If lpOverlapped is not NULL, lpBytesReturned can be NULL. If this parameter is not NULL and the operation returns data, lpBytesReturned is meaningless until the overlapped operation has completed. To retrieve the number of bytes returned, call GetOverlappedResult. If hDevice is associated with an I/O completion port, you can retrieve the number of bytes returned by calling GetQueuedCompletionStatus.


A pointer to an OVERLAPPED structure.

If hDevice was opened without specifying FILE_FLAG_OVERLAPPED, lpOverlapped is ignored.

If hDevice was opened with the FILE_FLAG_OVERLAPPED flag, the operation is performed as an overlapped (asynchronous) operation. In this case, lpOverlapped must point to a valid OVERLAPPED structure that contains a handle to an event object. Otherwise, the function fails in unpredictable ways.

For overlapped operations, DeviceIoControl returns immediately, and the event object is signaled when the operation has been completed. Otherwise, the function does not return until the operation has been completed or an error occurs.

Return value

If the operation completes successfully, DeviceIoControl returns a nonzero value.

If the operation fails or is pending, DeviceIoControl returns zero. To get extended error information, call GetLastError.


If the partition is on a disk formatted as type master boot record (MBR), partition size totals cannot exceed 2 TB per MBR disk. For example, a disk of type MBR can have a single 2-TB partition, two 1-TB partitions, or any combination that does not total more than 2 TB. If more space is required, a disk formatted as type GUID partition table (GPT) should be used. If third-party partitioning tools are used to work around this limitation on disks of type MBR larger than 2 TB, configuration operations via the disk partitioning IOCTL control codes will be limited.


Minimum supported client

Windows XP [desktop apps only]

Minimum supported server

Windows Server 2003 [desktop apps only]


WinIoCtl.h (include Windows.h)

See also

Disk Management Control Codes