SSC-4: Handling logical object counts greater than 4-bytes

[Kevin D Butt]

Formatted message: <a href="http://www.t10.org/cgi-bin/ac.pl?t=r&f=r0909102_f.htm">HTML-formatted message</a>

Tapeheads,
I believe that we should add as one of the items for SSC-4 how to safely 
allow a greater number of logical objects to be stored on medium than can 
be represented by a 4-byte field. 
Today we have the Locate (10) and the Locate (16) where one uses a 4-byte 
field and the other uses an 8-byte field.
However, if there are greater than 2^4 logical objects the Locate(10) 
cannot represent that.	SSC-4 should clearly address what happens in this 
case.  There should be a model section where this issue is discussed and 
the method for resolving it.  This may be contained in responses to 
specific commands or there may need to be a more elaborate method.  I 
think to be safe a more elaborate method will be needed.
I plan to ask the groups opinion about the need to add this to the list of 
SSC-4 items.
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