RE: Review of the 07 draft

["Robert Griswold" <rgriswold@Crossroads.com>]

Deva:

I would argue that having two ways to change the same thing adds
flexibility, rather than complexity.  If the iSCSI Text Messages are
allowed to change iSCSI only parameters, then the transport has access
to what it needs.  In addition, if the SCSI utility is aware of iSCSI
mode pages (which of course it would need to be to even understand
accessing iSCSI pages), then only one interface is needed for all
aspects of the target.  As stated by Eddy, the legacy of SCSI is that
mode pages, irrespective of what those parameters are manipulating
(transport, commands, responses, timing, etc.), are accessible through
SCSI mode commands.  

If mode page changes were not allowed to modify existing communication
parameters (for existing connections), then there is no problem.  Once
all active connections were dropped, then the re-establishment of
connections would present new defaults for critical iSCSI or SCSI
parameters.  Does this sound reasonable?

Bob

Robert Griswold
Technologist
Crossroads Systems, Inc.
512-928-7272

 -----Original Message-----
From: 	Dev [mailto:deva@stargateip.com] 
Sent:	Thursday, August 09, 2001 7:33 PM
To:	Robert Griswold; Eddy Quicksall; Jim Hafner
Cc:	ips@ece.cmu.edu
Subject:	RE: Review of the 07 draft

All,

I tend to disagree. The parameters for the iSCSI are negotiated between
the
initiator and target.
If we allow the parameters to be changed through SCSI Mode select, how
will
this work?

If parameters can be changed through SCSI Mode select then it will apply
only to Lead only connections.

So, we'll have

a) two methods to change the Lead only parameters common for the entire
session (one through mode select
and the other through text parameters)
b) Just iSCSI text command to change the connection specific parameters.

Does it not add to complexity having multiple ways to change the same
stuff?

Thanks

Deva
Platys communications

-----Original Message-----
From: owner-ips@ece.cmu.edu [mailto:owner-ips@ece.cmu.edu]On Behalf Of
Robert Griswold
Sent: Thursday, August 09, 2001 1:36 PM
To: Eddy Quicksall; Jim Hafner
Cc: ips@ece.cmu.edu
Subject: RE: Review of the 07 draft


Eddy:

I actually have no problem with all mode pages (SCSI and iSCSI) being
accessible and changeable from standard SCSI mode commands.  My initial
response to this section was to propose a method that would be
acceptable to the authors of the iSCSI draft.  If there is desire in the
group to allow mode pages for the entire target to be manipulated from
the SCSI level, I think that is a better idea that the one I proposed.
I would assume that an iSCSI aware SCSI utility would understand the
iSCSI specific settings, and allow the user to make those changes.  What
I am really against, is the ability to modify standard SCSI mode page
settings from text messages, as that could lead to target behavior
changes outside of the understanding of the SCSI nexus.

To recap your thinking:  Allow iSCSI text messages to modify and read
iSCSI only mode settings (potentially allowing the reading if SCSI mode
settings), but allow SCSI mode commands to modify and read all target
mode settings, including iSCSI settings.  Is that what you are saying.
If so, I agree.

Bob

Robert Griswold
Technologist
Crossroads Systems, Inc.
512-928-7272

 -----Original Message-----
From: 	Eddy Quicksall [mailto:ESQuicksall@hotmail.com]
Sent:	Thursday, August 09, 2001 2:08 PM
To:	Robert Griswold; Jim Hafner
Cc:	ips@ece.cmu.edu
Subject:	Re: Review of the 07 draft

I don't like the idea of not letting a user of a SCSI utility be able to
change some of the parameters for iSCSI. Because they may be relevant to
him
and there may not be a user interface to the iSCSI driver. pSCSI sets
these
low level parameters via a standard mode set, so why not iSCSI?

It would be best if we could work out something where only the SCSI
layer
can set the mode pages. That would solve everything.

Eddy

----- Original Message -----
From: "Jim Hafner" <hafner@almaden.ibm.com>
To: "Robert Griswold" <rgriswold@Crossroads.com>
Cc: <ips@ece.cmu.edu>
Sent: Friday, August 03, 2001 5:26 PM
Subject: Re: Review of the 07 draft

> Well, in fact, the draft is supposed to say that MODE_SELECT for the
> transport-specific mode page will NOT be done via SCSI, only via Text
> commands.  I read that as saying that from the SCSI layer, all fields
in
> these pages are "unchangeable" (even though they can change in the
iSCSI
> layer).  Of course, the draft doesn't say whether MODE PARAMETERS HAVE
> CHANGED unit attentions get thrown up at the SCSI layer when this
happens
> at the iSCSI layer.... You later have a clarifying question (Section
3) on
> this as well.
>
> Regards,
> Jim Hafner
>
>
>
>