RE: iSCSI : Command Ordering Proposal.

["Douglas Otis" <dotis@sanlight.net>]

Matt,

View iSCSI as isolated from either SCSI or TCP.  Mixing SCSI tags or TCP
Acks with Client/Server sequencing is confusing.  By resources, I was
focused only on the iSCSI function and not either TCP or SCSI.  From the
client's perspective, its PDU is sent only if acknowledged. This is where
you run into definitions of when is a PDU delivered to the target.  The same
should be true for the server and this send resource is my focus.  Rather
than fully using this handshake, a restart of the SCSI command is seen as
recovery but then we lose sense of sequence nor is there a  reliable link.

Doug

> Douglas Otis wrote:
> >
> > Matt,
> >
> > Whether you use the CmdSN or the tag to associate the retry,
> the CmdSN is
> > still used as a means to handshake freeing of resources and not the tag.
>
> You are wrong.  It specifically states in the document in 1.2.2.1:
>
> "CmdRNs are significant only during command delivery to the target.
> Once the device serving part of the target SCSI has received a
> command, CmdRN ceases to be significant."
>
> Any resources the target allocates must be based on the task tag.
>
> -Matt