Read Position reporting of Configurable EW

Kevin D Butt kdbutt at
Wed May 23 14:04:03 PDT 2007

Formatted message: <A HREF="r0705231_f.htm">HTML-formatted message</A>

I have a proposal in the SSC-3 working group that allows an application 
client to configure a zone before EW that will cause a check condition be 
returned when the first attempt to write data in it is made.  The intent 
(though not the only use) is to allow for application clients to empty any 
of their host buffers.	The current EW conditions still apply and allow 
for device buffers to be emptied. 
This proposal is "07-218r1 SSC: Configurable EW" and can be found at
One outsanding issue is how to report this in the Read Position command. A 
note to this question can be found in the proposal posted at the above 
location. The two possibilities are to have Read Position data indicate 
that current position of medium is:
1) between the Programmed Early Warning position and End-of-partition 
2) between the Programmed Early Warning position and Early Warning (EW). 
If this option is chosen, then the indication would be turned off between 
EW and EOP.  This would make it possible that the indication for being 
between the Programmed Early Warning position and EW would never be seen 
by the application client (i.e. this zone was completely traversed without 
a Read Position command being issued and the current position is now 
between EW and EOP)
If you have a preference, please contact me at kdbutt at or 
respond to the reflector at t10 at
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 at

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