RE: sector alignment for DataOut PDUs?

[Robert Snively <rsnively@Brocade.COM>]

There has always been a feeling that it was nice to do things
on convenient boundaries, including memory page boundaries and
device physical block boundaries, but SCSI has long since 
elected to perform any operation on almost any boundary.  SCSI drives
and related operating systems have commonly used block sizes of 512
bytes and 520 bytes and less commonly of other values.  

The only requirement we were able to enforce in previous
SCSI protocols is that all but the last PDU of a transfer
were required to be on 4 byte boundaries.  We were also
able to enforce the maximum values and a requirement that
the transferred data count exactly match the requested byte
count.

I would strongly suggest that you not bother to enforce any
other boundary restrictions.

I believe Eddy was right when he asked:

	Given that the TCP issues of reassembly 
	are so much more complicated than
	the concatenation issues necessary for 
	target data alignment, is there
	really a problem here?

My answer to him would be, no, there is not a problem.

Bob Snively                        e-mail:    rsnively@brocade.com
Brocade Communications Systems     phone:  408 487 8135
1745 Technology Drive
San Jose, CA 95110