sbc3r24 referrals clarifications

Penokie, George George.Penokie at lsi.com
Wed Sep 8 08:41:49 PDT 2010


* From the T10 Reflector (t10 at t10.org), posted by:
* "Penokie, George" <George.Penokie at lsi.com>
*
Hannes,
The allocation length field size for REPORT REFERRALS is currently 4 bytes.
Although, I get the point of your comment. There is no good reason why the
size of the USER DATA SEGMENT REFERRAL DESCRIPTOR LENGTH field is only 2
bytes, that was the size that the people who wanted the feature were happy
with. If you would like to expand it to 4 bytes then you will have to bring
in a proposal to the SCSI committee for such a change.
Bye for now, 
George Penokie
LSI Corporation 
3033 41st St. NW 
Suite 100 
Rochester, MN 55901
507-328-9017 
george.penokie at lsi.com
-----Original Message-----
From: Hannes Reinecke [mailto:hare at suse.de] 
Sent: Wednesday, September 08, 2010 4:53 AM
To: Penokie, George
Cc: t10 at t10.org
Subject: Re: sbc3r24 referrals clarifications
Penokie, George wrote:
> Hannes,
> 
> The statement would have been more clear stated as:
> 
> The user data segment referral descriptor (see table 10) is defined in the
user data segment referral sense data descriptor.
> 
> The format of the user data segment referral descriptor that is used in the
REPORT REFERRALS parameter data is defined in table 10.
> 
Thanks for your clarification.
There is actually another point wrt referrals:
The REPORT REFERRALS command allows you to specify up to 8 bytes of
allocation length.
Yet the parameter data returned allow you to specify only up to _2_
bytes for returned data (namely byte 2 & 3), with the top 2 bytes
remaining reserved.
Shouldn't those two numbers be aligned?
I would actually prefer to lower the size for the allocation length
to 4 bytes and raise the size for the parameter size to 4 bytes.
Otherwise the standard would impose quite a limitation on
the number of possible user segments, making it unusable for some
application scenarios.
Thanks for your time.
Cheers,
Hannes
-- 
Dr. Hannes Reinecke		      zSeries & Storage
hare at suse.de			      +49 911 74053 688
SUSE LINUX Products GmbH, Maxfeldstr. 5, 90409 Nürnberg
GF: Markus Rex, HRB 16746 (AG Nürnberg)
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