Re: iscsi : default iscsi mode page settings.

["Sanjeev Bhagat \(TRIPACE/Zoetermeer\)" <iscsi_t10@sanjeevbhagat.com>]

well we are now debating two things

1. Whether Firstburstsize comes in iSCSI realm or does it come in SCSI
realm.
2. Whether Firstburstsize should be sent as login key or should it be a part
of mode sense/select page

For the first point, As charles explained below Firstburstsize is a part of
data delievery system (transport layer as described in SAM-2), so it
certainly is not a parameter of SCSI. . SCSI as such does not even need to
have any Firstburstsize because it is capable of transferring any amount of
data. Firstburstsize basically only helps in faster implementation of data
being transferred on network.

As such the "SCSI Mode Pages" as described in iSCSI document should rather
be renamed to iSCSI Mode pages.

I think the FirstBurstSize be kept as login key but here we will have a
problem as to which value be over-ridden whether the one sent by initiator
or target. This depends upon whether

a. the iSCSI target should be made so efficient as to support different
values of Firstburstsize for different initiators. If it is so then the
target accepts the Initiator value. This increases complexity on target side
or
b. the iSCSI target should operate on one particular mode of FirstBusSize.
If it is so then initiator accepts target value. But in this case also I
foresee a problem in this case when multiple intiators are accessing a iSCSI
target and one of the iSCSI initiator changes the value of FirstBusSize

If we keep FirstBurstSize as a part of mode sense/mode select page then the
problem described above in (b) still exists

Regards,
Sanjeev


----- Original Message -----
From: "Binford, Charles" <CBinford@pirus.com>
To: "'Julian Satran'" <Julian_Satran@il.ibm.com>; <ips@ece.cmu.edu>
Sent: Monday, September 24, 2001 4:00 PM
Subject: RE: iscsi : default iscsi mode page settings.


> I believe it is the transport's job to deliver the data.  Buffering
> unsolicited data that has arrived at the target *before* the SCSI engine
has
> even had a chance to evaluate the CDB is part of the data delivery
system -
> the transport.
>
> Charles Binford
> Pirus Networks
> 316.315.0382 x222
>
>
> -----Original Message-----
> From: Julian Satran [mailto:Julian_Satran@il.ibm.com]
> Sent: Friday, September 21, 2001 11:06 PM
> To: ips@ece.cmu.edu
> Subject: Re: iscsi : default iscsi mode page settings.
>
>
>
>
> That is not my reading of the map. The unsolicited payload buffer size is
a
> "data sink" attribute. The data sink is the SCSI engine and not the iSCSI
> layer.
>
> Julo
>
>
>
>
>                     Santosh Rao
>
>                     <santoshr@cup.       To:     ips@ece.cmu.edu
>
>                     hp.com>              cc:
>
>                     Sent by:             Subject:     Re: iscsi : default
> iscsi mode
>                     owner-ips@ece.        page settings.
>
>                     cmu.edu
>
>
>
>
>
>                     21-09-01 21:50
>
>                     Please respond
>
>                     to Santosh Rao
>
>
>
>
>
>
>
>
>
> Julian,
>
> The FirstBurstSize is governing an iscsi parameter which is : "how much
> un-solicited
> data can the initiator send" ? I concur with Charles' suggestion that
> FirstBurstSize be
> moved to a login key.
>
> By doing this, we can improve scan times, due to the elimination of the
> mode
> sense/select & avoid the side effects of shared mode pages. This allows
> easier use of
> un-solicited data.
>
> Regards,
> Santosh
>