Saveable mode pages

Kevin D Butt kdbutt at us.ibm.com
Wed Feb 11 14:02:29 PST 2015


Formatted message: <a href="http://www.t10.org/cgi-bin/ac.pl?t=r&f=r1502111_f.htm">HTML-formatted message</a>

I am confused by 6.12.5 Saved values 
<<All saveable mode pages should be considered saved if a MODE SELECT 
command issued with the SP bit set to one has completed with a GOOD status 
or after the successful completion of a FORMAT UNIT command.>>
This states that after the successful completion of a FORMAT UNIT command 
ALL saveable mode pages should be considered saved. This may be good for 
block devices, but why are tape devices included in this? On tape devices 
a FORMAT UNIT command formats the tape but does not change other things in 
the device - nor do we want it to.  Also, I can interpret this to say, 
when doing a FORMAT UNIT command part of the processing is to take all the 
Current values of mode pages that are saveable and save them. This may 
violate the intent of the application client which explicitly did not set 
the SP bit in the MODE SELECT that updated the Current values (and 
explicitly did not update them to Saved values).
Is anybody else bothered by this?
Kevin D. Butt
SCSI Architect, Tape Firmware, CAMSS
T10 Standards
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



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