Note

Access to this page requires authorization. You can try signing in or .

Access to this page requires authorization. You can try .

FSCTL_SET_ZERO_ON_DEALLOCATION IOCTL (winioctl.h)

Indicates an NTFS file system file handle should have its clusters filled with zeros when it is deallocated. If a file is resident, it is converted to nonresident. When clusters are deallocated, the clusters on a disk are zeroed. If a file is deleted, all clusters associated with the file are zeroed.

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

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

Remarks

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

Technology Supported
Server Message Block (SMB) 3.0 protocol Yes
SMB 3.0 Transparent Failover (TFO) Yes
SMB 3.0 with Scale-out File Shares (SO) Yes
Cluster Shared Volume File System (CsvFS) Yes
Resilient File System (ReFS) No

Requirements

Requirement Value
Minimum supported client Windows Vista [desktop apps only]
Minimum supported server Windows Server 2008 [desktop apps only]
Header winioctl.h (include Windows.h)

See also

Feedback

Was this page helpful?

Additional resources

  • Last updated on