Re: iSCSI: Check Condition and Residuals

[Santosh Rao <santoshr@cup.hp.com>]

Luben Tuikov wrote:

> Santosh Rao wrote (Thu, 01 Aug 2002 10:11:48 -0700):
> > Julian & Robert [Russell],
> >
> > I raised the same query regarding RESID for FCP/FCP-2 this time last
> > year. The response I got for FCP/FCP-2 was that RESID information shall
> > be valid, regardless of the scsi status returned. The RESID field, can
> > be checked by the scsi transport drivers independent of the SCSI STATUS.
> THIS-------------------------------------->^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
> > I have enclosed the T10 response from Rob Snivelly below on that issue.
> > As per FC-PLDA, the RESID information is valid, regardless of the scsi
> > status returned by the device.
> >
> > An example of this is the case of "NO SENSE" or "RECOVERED ERROR" check
> > condition, when the data transfer may have taken place and a CHECK
> > CONDITION is returned. Also, for other CHECK CONDITION status', partial
> > data transfer may have taken place and hence, resid information should
> > be present.
> 
> This alone is CLEARLY implying that targets look up the residuals
> right in the sense data, which is totally wrong. (Repeating myself
> here again.)



My mail raised the question of when FCP-x initiator scsi transport
drivers can examine the resid field. This has nothing to do with
targets. I made no mention of targets peeking into sense data. 

Please read the complete mail properly in its full context before
arriving at conclusions.

- Santosh