The IOCTL_DISK_GET_DRIVE_GEOMETRY DeviceIoControl operation returns information about the physical disk's geometry: type, number of cylinders, tracks per cylinder, sectors per track, and bytes per sector.
dwIoControlCode = IOCTL_DISK_GET_DRIVE_GEOMETRY; // operation code
lpInBuffer = NULL; // address of input buffer; not used; must be NULL
nInBufferSize = 0; // size of input buffer; not used; must be zero
lpOutBuffer ; // address of output buffer
nOutBufferSize ; // size of output buffer
lpBytesReturned ; // address of actual bytes of output
Parameters
lpInBuffer
Points to an input buffer. Not used with this operation. Set to NULL.
nInBufferSize
Specifies the size, in bytes, of the buffer pointed to by lpInBuffer. Not used with this operation. Set to zero.
lpOutBuffer
Points to a buffer that will receive a DISK_GEOMETRY data structure.
nOutBufferSize
Specifies the size, in bytes, of the buffer pointed to by lpOutBuffer, which must be greater than or equal to the size of a DISK_GEOMETRY data structure.
lpBytesReturned
Points to a DWORD that receives the actual size, in bytes, of the data stored into lpOutBuffer.
Return Values
If the operation succeeds, DeviceIoControl returns TRUE.
If the operation fails, DeviceIoControl returns FALSE. To get extended error information, call GetLastError.
Remarks
This device I/O control operation is for disk devices.
See Also