To: t10@t10.org
Subject: SSC-3: EW vs. VOLUME OVERFLOW
From: Kevin D Butt <kdbutt@us.ibm.com>
Date: Fri, 3 Oct 2008 12:49:08 -0700
X-Message-Number: 9173
Formatted message: HTML-formatted message

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/