SCSI Miniport AlignmentMask Restrictions (153264)


The information in this article applies to:

  • Microsoft Win32 Device Driver Kit (DDK) for Windows NT 3.5
  • Microsoft Win32 Device Driver Kit (DDK) for Windows NT 3.51
  • Microsoft Win32 Device Driver Kit (DDK) for Windows NT 4.0
  • Microsoft Windows 2000 Driver Development Kit (DDK)
  • Microsoft Windows XP Driver Development Kit (DDK)
This article was previously published under Q153264

SUMMARY

SCSI miniport drivers indicate the alignment restrictions of scatter/gather buffer pointers in the AlignmentMask field of the PORT_CONFIGURATION_INFORMATION structure. The maximum alignment supported by Windows NT is 0x7. This setting yields cache-aligned buffers.

In theory, a larger AlignmentMask could be specified by the SCSI miniport, but the file systems layered above the driver cannot honor the alignment request, so they will eventually fail.

MORE INFORMATION

Refer to the Windows NT Device Driver Kit documentation for details on SCSI miniport design.
Modification Type:MinorLast Reviewed:5/24/2004
Keywords:KB153264
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