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NTFS_VOLUME_DATA_BUFFER structure (winioctl.h)

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Represents volume data. This structure is passed to the FSCTL_GET_NTFS_VOLUME_DATA control code.

Syntax

typedef struct {
  LARGE_INTEGER VolumeSerialNumber;
  LARGE_INTEGER NumberSectors;
  LARGE_INTEGER TotalClusters;
  LARGE_INTEGER FreeClusters;
  LARGE_INTEGER TotalReserved;
  DWORD         BytesPerSector;
  DWORD         BytesPerCluster;
  DWORD         BytesPerFileRecordSegment;
  DWORD         ClustersPerFileRecordSegment;
  LARGE_INTEGER MftValidDataLength;
  LARGE_INTEGER MftStartLcn;
  LARGE_INTEGER Mft2StartLcn;
  LARGE_INTEGER MftZoneStart;
  LARGE_INTEGER MftZoneEnd;
} NTFS_VOLUME_DATA_BUFFER, *PNTFS_VOLUME_DATA_BUFFER;

Members

VolumeSerialNumber

The serial number of the volume. This is a unique number assigned to the volume media by the operating system.

NumberSectors

The number of sectors in the specified volume.

TotalClusters

The number of used and free clusters in the specified volume.

FreeClusters

The number of free clusters in the specified volume.

TotalReserved

The number of reserved clusters in the specified volume.

BytesPerSector

The number of bytes in a sector on the specified volume.

BytesPerCluster

The number of bytes in a cluster on the specified volume. This value is also known as the cluster factor.

BytesPerFileRecordSegment

The number of bytes in a file record segment.

ClustersPerFileRecordSegment

The number of clusters in a file record segment.

MftValidDataLength

The length of the master file table, in bytes.

MftStartLcn

The starting logical cluster number of the master file table.

Mft2StartLcn

The starting logical cluster number of the master file table mirror.

MftZoneStart

The starting logical cluster number of the master file table zone.

MftZoneEnd

The ending logical cluster number of the master file table zone.

Remarks

Reserved clusters are the free clusters reserved for later use by Windows.

The NTFS_VOLUME_DATA_BUFFER structure represents the basic information returned by FSCTL_GET_NTFS_VOLUME_DATA. For extended volume information, pass a buffer that is the combined size of the NTFS_VOLUME_DATA_BUFFER and NTFS_EXTENDED_VOLUME_DATA structures. Upon success, the buffer returned by FSCTL_GET_NTFS_VOLUME_DATA will contain the information associated with both structures. The NTFS_VOLUME_DATA_BUFFER structure will always be filled starting at the beginning of the buffer, with the NTFS_EXTENDED_VOLUME_DATA structure immediately following. The NTFS_EXTENDED_VOLUME_DATA structure is defined as follows:

C++ 
typedef struct {
    ULONG ByteCount;
    USHORT MajorVersion;
    USHORT MinorVersion;
} NTFS_EXTENDED_VOLUME_DATA, *PNTFS_EXTENDED_VOLUME_DATA;
This structure contains the major and minor version information for an NTFS volume. The ByteCount member will return the total bytes of the output buffer used for this structure by the call to FSCTL_GET_NTFS_VOLUME_DATA. This value should be sizeof(NTFS_EXTENDED_VOLUME_DATA) if the buffer passed was large enough to hold it, otherwise the value will be less than sizeof(NTFS_EXTENDED_VOLUME_DATA).

Requirements

Requirement Value
Minimum supported client Windows XP [desktop apps only]
Minimum supported server Windows Server 2003 [desktop apps only]
Header winioctl.h (include Windows.h)

See also

FSCTL_GET_NTFS_VOLUME_DATA