To: "Peterson, Dave" <dpeterso@brocade.com>
Cc: "Knight, Frederick" <Frederick.Knight@netapp.com>, t10@t10.org
Subject: RE: SSC-3: EW vs. VOLUME OVERFLOW
From: Kevin D Butt <kdbutt@us.ibm.com>
Date: Mon, 6 Oct 2008 17:04:32 -0700
X-Message-Number: 9179
Formatted message: HTML-formatted message

Dave,
I have been asked to try to get this into SSC-3.  The device driver 
developer, Ellen, is writing a proposal which I will help put into 
standardeze.  She wants me to try to get it into SSC-3 because she thinks 
it needs to get in sooner rather than later.
We have a committed party (IBM) to write the proposal and a document 
number:
08-406r0 - SSC-3: Clarifying when sense data bits are set 
I am requesting that an item be added to the SSC-3 agenda for a vote on 
the following motion:
Kevin Butt made a motion that a late letter ballot comment against SSC-3 
be accepted that reads, "There needs to be added to SSC-3 clarifications 
of the conditions that cause the EOM, ILI, and Filemark bits to be set in 
the sense data.  Also the interactions between EW and Volume Overflow need 
clarified.  These clarifications need to be added to the sections 
describing each of the affected commands and a model section needs to be 
added and that model section needs to include a table for easier 
reference."
Thanks,
Kevin D. Butt
SCSI & Fibre Channel Architect, Tape Firmware
MS 6TYA, 9000 S. Rita Rd., Tucson, AZ 85744
Tel: 520-799-2869 / 520-799-5280
Fax: 520-799-2723 (T/L:321)
Email address: kdbutt@us.ibm.com
http://www-03.ibm.com/servers/storage/ 
From:
"Knight, Frederick" <Frederick.Knight@netapp.com>
To:
Kevin D Butt/Tucson/IBM@IBMUS
Date:
10/03/2008 04:22 PM
Subject:
RE: SSC-3: EW vs. VOLUME OVERFLOW
SSC-4
From: Kevin D Butt [mailto:kdbutt@us.ibm.com] 
Sent: Friday, October 03, 2008 3:49 PM
To: t10@t10.org
Subject: SSC-3: EW vs. VOLUME OVERFLOW
Tapeheads, 
I have received the following communication from a Device Driver 
implementer who is an experienced device driver implementer for block 
devices but just started to get involved with tape.  I have been asked 
several questions and clarifications with regard to the standards.  This 
statement I received from her is essentially an implied request to improve 
SSC-3. 
<<My main goal is to figure out how to organize my error recognition code 
so that I can tell early warning from physical end of tape, etc.   I'm 
just having a hard time pulling out of the standard the minimum of what a 
device has to do so my handling for the basics can be universal.  It 
appears that I have to know the bit settings and the sense data in order 
to tell early warning from physical end of media.  It also appears that I 
might have to know if it is a read or write.  It sure would be nice to 
have it spelled out in a table in the standard.>> 
As such, I have the following questions. 
1) Do we believe that SSC-3 would be improved by adding such information? 
2) If yes, do we want to put it into SSC-3 or SSC-4? 
If we think it should be in SSC-3 we will need to vote on accepting 
another Late letter ballot comment.  I personally see no reason why this 
request would be urgent and I would probably vote for inclusion into SSC-4 
unless somebody else volunteered to write the proposal. 
Thanks, 
Kevin D. Butt
SCSI & Fibre Channel Architect, Tape Firmware
MS 6TYA, 9000 S. Rita Rd., Tucson, AZ 85744
Tel: 520-799-2869 / 520-799-5280
Fax: 520-799-2723 (T/L:321)
Email address: kdbutt@us.ibm.com
http://www-03.ibm.com/servers/storage/