Ted MacNEIL wrote:
This would allow a migration path, better disk I-O routines because FBA wouldn't have to be mapped to CKD.
Why?
Better than what?
2-5 ms per I/O is not an issue!
What are we to gain with FBA, these days?
(From somebody who remembers 50-60 ms per I/O)
It sounds as if they're concerned about the application or operating
system "math" required to convert an "emulated FBA sector number" to
CCCCcccHR. You have to divide by some RPT (records per track) value to
get track and record number. Then divide track by 15 to get cylinder,
track, and record.
I honestly don't know how often this sort of thing is being done. But,
with the speed of today's machines, it's hard to imagine it accounts for
much if any measurable performance "drag" -- especially when compared
to speed of the I/O itself.
--
Edward E Jaffe
Phoenix Software International, Inc
5200 W Century Blvd, Suite 800
Los Angeles, CA 90045
310-338-0400 x318
[EMAIL PROTECTED]
http://www.phoenixsoftware.com/
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