DEVICE_COPY_OFFLOAD_DESCRIPTOR structure (winioctl.h)
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
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[2]
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
| Requirement | Value |
|---|---|
| Minimum supported client | Windows 8 [desktop apps only] |
| Minimum supported server | Windows Server 2012 [desktop apps only] |
| Header | winioctl.h (include Windows.h) |