Re: iSCSI: AHS drop bit

["Mallikarjun C." <cbm@rose.hp.com>]

Julian,

> We don't have any use for it but some "vendor specific" extensions may.

That then begs the question - should/can we anticipate vendor-specific needs
and provide for them in the spec?

My preference is to do away with AHS drop bit - since it doesn't seem
useful to either iSCSI or SCSI.

Regards.
--
Mallikarjun

Mallikarjun Chadalapaka
Networked Storage Architecture
Network Storage Solutions Organization
Hewlett-Packard MS 5668
Roseville CA 95747

----- Original Message -----
From: "Julian Satran" <Julian_Satran@il.ibm.com>
To: <ips@ece.cmu.edu>
Sent: Saturday, January 05, 2002 6:10 AM
Subject: Re: iSCSI: AHS drop bit


> Mallikarjun,
>
> The bit was really meant to enable dropping the additional header and not
> the whole request if ignored but rejecting the whole request.
> We don't have any use for it but some "vendor specific" extensions may.
>
> I suggest we change the wording of non-ISCSI non-iSCSI/vendor specific
>
> Julo
>
>
>
>                     "Mallikarjun
>                     C."                  To:     ips <ips@ece.cmu.edu>
>                     <cbm@rose.hp.c       cc:
>                     om>                  Subject:     iSCSI: AHS drop bit
>                     Sent by:
>                     owner-ips@ece.
>                     cmu.edu
>
>
>                     14-12-01 22:48
>                     Please respond
>                     to cbm
>
>
>
>
>
> Julian,
>
> Section 3.2.2.1 says the following on the AHS drop bit -
>            bit 7 - Drop Bit - if set to 1 this AHS may be ignored if not
>            understood; if set to 0 this AHS must be rejected if not
>            understood.
>
> - I suspect it is the entire command that was meant to be failed, not
>   just the AHS...
>
> - If it is a SCSI operation that is being failed, I suggest that
>   the target should end the command with an appropriate SCSI CHECK
>   CONDITION - so the command sequence window can advance at the
>   transport level (and the inability of the target to support say
>   extended CDB is known end-to-end, to prevent fruitless SCSI retries).
>
> - This bit may be useful for AHS code "Non-iSCSI extensions", but
>   I could not see how it can be used for the defined iSCSI operations.
>   If it is indeed so, I would actually suggest dropping this feature.
>
> Regards.
> --
> Mallikarjun
>
>
> Mallikarjun Chadalapaka
> Networked Storage Architecture
> Network Storage Solutions Organization
> MS 5668         Hewlett-Packard, Roseville.
> cbm@rose.hp.com
>
>
>
>
>