SSC-4: ERASE(16) command description flaw?

Kevin D Butt kdbutt at us.ibm.com
Fri Apr 23 09:38:47 PDT 2010


Formatted message: <a href="http://www.t10.org/cgi-bin/ac.pl?t=r&f=r1004231_f.htm">HTML-formatted message</a>

Tim,
In the ERASE(16) command, the CDB carries the Partition and LBA of the 
location to begin the erase operation.	The medium is to be located to 
that position then the erase begin.  If the locate to the initial position 
fails that failure occurs before the erase operation has begun.  Hence, 
the setting of the LONG bit that is used in the erase operation should 
have no bearing on the locate operation.
Thanks,
Kevin D. Butt
SCSI & Fibre Channel Architect, Tape Firmware
MS 6TYA, 9000 S. Rita Rd., Tucson, AZ 85744
Tel: 520-799-5280
Fax: 520-799-2723 (T/L:321)
Email address: kdbutt at us.ibm.com
http://www-03.ibm.com/servers/storage/ 
From:
Tim Jones <tjmac at tolisgroup.com>
To:
t10 at t10.org
Date:
04/23/2010 09:10 AM
Subject:
Re: SSC-4: ERASE(16) command description flaw?
Sent by:
owner-t10 at t10.org
* From the T10 Reflector (t10 at t10.org), posted by:
* Tim Jones <tjmac at tolisgroup.com>
*
I believe that the question should be "What happens if a locate operation 
fails when the LONG bit **IS** set to 1?"  Is there a difference in the 
task that must then be performed to resolve the failure?
Tim
--
Tim Jones	 tjmac at tolisgroup.com
President/CTO								 
http://www.tolisgroup.com
TOLIS Group, Inc.						 
http://www.productionbackup.com
480-505-0488 x227 480-505-0492 (fax)
BRU ... Because it's the RESTORE that matters
On Apr 22, 2010, at 6:12 PM, Kevin D Butt wrote:
> 
> In reading SSC-4, ERASE(16) command I am confused by the last sentence 
in this paragraph: 
> 
> <<The partition and logical object identifier fields specify the 
position at which the ERASE(16) command shall start. If the current 
position does not match the specified logical object identifier and 
partition fields, the device server shall perform a locate operation to 
the specified logical object identifier and partition prior to performing 
the erase operation. If the locate operation fails, the device server 
shall return CHECK CONDITION status and the additional sense code shall be 
set to LOCATE OPERATION FAILURE. The logical position is undefined 
following a locate operation failure with a LONG bit of zero.>> 
> 
> Why does the value of the LONG bit make any difference in whether or not 
the position after a failed locate operation is defined?  I think this 
sentence is not accurate and should be modified to read, "The logical 
position is undefined following a locate operation failure." 
> 
> Thanks, 
> 
> Kevin D. Butt
> SCSI & Fibre Channel Architect, Tape Firmware
> MS 6TYA, 9000 S. Rita Rd., Tucson, AZ 85744
> Tel: 520-799-5280
> Fax: 520-799-2723 (T/L:321)
> Email address: kdbutt at us.ibm.com
> http://www-03.ibm.com/servers/storage/
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