Using a sector number of x'00' effectively disabled RPS on devices that did care.


Edward Jaffe wrote:
Richards.Bob wrote:
Do you know of any DASD subsystem that does not publish RPM information?
I thought not. They still "care". <grin>
But kidding aside, I would suspect the last time it "really mattered" it
would be a real 3990-3390 SLED.

Am I missing something in your question here?

I assume RPS sector numbers are *ignored* for ESS and newer devices. But, the IBM documentation does not confirm my assumption. Rather, they still fully document the RPS factors that are returned, how to calculate the sector value, etc.

I noticed the tuning Redbook said that RPS delays cannot occur on ESS. But, says nothing about what, if anything, the sector number you (are expected to?) provide might be used for.

Setting the sector number to x'FF' in the ECKD locate record parameter list disables the use of RPS. I'd like to see us do that for all modern DASD devices.


--
Chris Langford,
Cestrian Software:
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