FSCTL_EXTEND_VOLUME IOCTL

Description

Increases the size of a mounted volume.

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

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

Parameters

Input buffer

Input buffer length

Output buffer

Output buffer length

Input/output buffer

Input/output buffer length

Status block

Irp->IoStatus.Status is set to STATUS_SUCCESS if the request is successful.

Otherwise, Status to the appropriate error condition as a NTSTATUS code.

For more information, see NTSTATUS Values.

Remarks

This control code is supported on NTFS, RAW, and ReFS file systems.

This control code cannot be used to reduce the size of a volume. The new volume size must be at least one cluster larger than the previous volume size. The underlying partition must have enough sectors to contain the extended volume. If not, IOCTL_DISK_GROW_PARTITION can be used if the underlying device has enough space available.

You can extend a live volume, and the volume can be open for sharing during the extend operation.

You do not need to lock a volume that you are extending, nor do you need to shut down other applications or services during the extend operation.

In Windows 8 and Windows Server 2012, this code is supported by the following technologies.

See also

• CreateFile
• DeviceIoControl
• FSCTL_SHRINK_VOLUME
• IOCTL_DISK_GROW_PARTITION
• Volume Management Control Codes