SCSI Miniport AlignmentMask Restrictions
Article ID: 153264
Article Last Modified on 2/12/2007
APPLIES TO
- Microsoft Win32 Device Driver Kit for Windows NT 3.5
- Microsoft Win32 Device Driver Kit for Windows NT 3.51
- Microsoft Win32 Device Driver Kit for Windows NT 4.0
- Microsoft Win32 Device Driver Kit for Windows 2000
- Microsoft Windows XP Driver Development Kit
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.
Additional query words: 3.50
Keywords: KB153264