FBA 4K block drive sold

[Mike Schwab]

The was a new setting added to the CCKD routine that shifted the
address pointer by a number in the header. The default was 9 for 512
sectors. Suggesting review for 4096 byte sector disks that are the
new standard.

---------- Forwarded message ----------
From: Anne & Lynn Wheeler <lynn-xGgpAy7L2e/QT0dZR+***@public.gmane.org>
Date: Wed, Oct 20, 2010 at 6:47 AM
Subject: Re: When will MVS be able to use cheap dasd
To: IBM-MAIN-***@public.gmane.org


from today

Western Digital Launches First 3TB Hard Drive
http://www.informationweek.com/news/storage/portable/showArticle.jhtml?articleID=227900320&itc=ref-true

mentions that it is a FBA4096 drive (rather than FBA512 that has been
standard for so long) & suggested retail is $239, $74/tbyte (2.5TB drive
is $189, $76/tbyte)

recent posts in comp.database.theory thread ... mentions future system
and s/38. one of the early isssues was that s/38 treated all disks as
one large pool (with potential scatter allocate across all disks) ... so
system backup was all available data and single disk failure resulted in
doing complete system restore (which was rumored could take days).
Supposedly this was motivation for s/38 being early adopter of raid
technology ... as countermeasure to single disk failure (since such
occurance was so traumatic).
http://www.garlic.com/~lynn/2010n.html#80 Hashing for DISTINCT or
GROUP BY in SQL
http://www.garlic.com/~lynn/2010n.html#81 Hashing for DISTINCT or
GROUP BY in SQL
http://www.garlic.com/~lynn/2010n.html#82 Hashing for DISTINCT or
GROUP BY in SQL
http://www.garlic.com/~lynn/2010n.html#83 Hashing for DISTINCT or
GROUP BY in SQL
http://www.garlic.com/~lynn/2010n.html#84 Hashing for DISTINCT or
GROUP BY in SQL
http://www.garlic.com/~lynn/2010n.html#85 Hashing for DISTINCT or
GROUP BY in SQL

even with million+ hr MTBF drives ... there is still some failures
... which has driven to RAID & hot-pluggable ... being able to
transparently handle (mask) single disk failure (and do replacement and
restore on-the-fly).

some recent posts mentioning the fba512 to fba4096 move:
http://www.garlic.com/~lynn/2010.html#1 DEC-10 SOS Editor Intra-Line Editing
http://www.garlic.com/~lynn/2010.html#84 locate mode, was Happy DEC-10 Day
http://www.garlic.com/~lynn/2010b.html#85 search engine history, was
Happy DEC-10 Day
http://www.garlic.com/~lynn/2010d.html#9 PDS vs. PDSE
http://www.garlic.com/~lynn/2010m.html#1 History of Hard-coded Offsets
http://www.garlic.com/~lynn/2010m.html#41 IBM 3883 Manuals

--
virtualization experience starting Jan1968, online at home since Mar1970

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