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DEVICE_COPY_OFFLOAD_DESCRIPTOR structure

The DEVICE_COPY_OFFLOAD_DESCRIPTOR structure is one of the query result structures returned from an IOCTL_STORAGE_QUERY_PROPERTY request. This structure contains the copy offload capabilities for a storage device.

Syntax

C++


typedef struct _DEVICE_COPY_OFFLOAD_DESCRIPTOR {
  DWORD     Version;
  DWORD     Size;
  DWORD     MaximumTokenLifetime;
  DWORD     DefaultTokenLifetime;
  DWORDLONG MaximumTransferSize;
  DWORDLONG OptimalTransferCount;
  DWORD     MaximumDataDescriptors;
  DWORD     MaximumTransferLengthPerDescriptor;
  DWORD     OptimalTransferLengthPerDescriptor;
  WORD      OptimalTransferLengthGranularity;
  BYTE      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 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: Reserved.

Remarks

This structure is returned from a IOCTL_STORAGE_QUERY_PROPERTY request when the PropertyId member of STORAGE_PROPERTY_QUERY is set to StorageDeviceCopyOffloadProperty.

Requirements

Minimum supported client	Windows 8 [desktop apps only]
Minimum supported server	Windows Server 2012 [desktop apps only]
Header	WinIoCtl.h (include Windows.h)

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