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DEVICE_COPY_OFFLOAD_DESCRIPTOR structure (ntddstor.h)

  • Article

Used in conjunction with the IOCTL_STORAGE_QUERY_PROPERTY request to describe the copy offload capabilities of a storage device.

Syntax

typedef struct _DEVICE_COPY_OFFLOAD_DESCRIPTOR {
  ULONG     Version;
  ULONG     Size;
  ULONG     MaximumTokenLifetime;
  ULONG     DefaultTokenLifetime;
  ULONGLONG MaximumTransferSize;
  ULONGLONG OptimalTransferCount;
  ULONG     MaximumDataDescriptors;
  ULONG     MaximumTransferLengthPerDescriptor;
  ULONG     OptimalTransferLengthPerDescriptor;
  USHORT    OptimalTransferLengthGranularity;
  UCHAR     Reserved[2];
} DEVICE_COPY_OFFLOAD_DESCRIPTOR, *PDEVICE_COPY_OFFLOAD_DESCRIPTOR;

Members

Version

Contains the size of this structure, in bytes. The value of this member will change as members are added to the structure.

Size

Specifies the total size of the data returned, in bytes. This may include data that follows this structure.

MaximumTokenLifetime

The maximum lifetime of the token, in seconds.

DefaultTokenLifetime

The default lifetime of the token, in seconds.

MaximumTransferSize

The maximum transfer size, in bytes.

OptimalTransferCount

The optimal transfer size, in bytes.

MaximumDataDescriptors

The maximum number of data descriptors.

MaximumTransferLengthPerDescriptor

The maximum transfer length, in blocks, per descriptor.

OptimalTransferLengthPerDescriptor

The optimal transfer length, in blocks, per descriptor.

OptimalTransferLengthGranularity

The granularity of the optimal transfer length, in blocks. Transfer lengths that are not an even multiple of this length may be delayed.

Reserved[2]

Reserved for future use.

Requirements

Requirement Value
Minimum supported client Windows 8
Minimum supported server Windows Server 2012
Header ntddstor.h (include Ntddstor.h)

See also

IOCTL_STORAGE_QUERY_PROPERTY