Re: IBM disk arm reduction "rule of thumb"

Unfortunately, I don't know of a rule of thumb.

However, this is why IBM is adding faster drives, and more cache on the
IOAs.

Al

Al Barsa, Jr.
Barsa Consulting Group, LLC

400>390

"i" comes before "p", "x" and "z"
e gads

Our system's had more names than Elizabeth Taylor!

914-251-1234
914-251-9406 fax

http://www.barsaconsulting.com
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http://www.as400connection.com



                                                                           
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Hello All,

Does anyone know if IBM has a "rule of thumb" on the acceptable level of
disk arm reductions?  We are in the process of developing a configuration
for a new 520.  Our current 820 has 18 disk arms.  One vendor suggests
reducing to 8 in the main box (no tower).  Another vendor recommends 12
utilizing a tower.  The reasoning is that at our current peak disk
accesses, we would need that many to keep the disk ops/second at 60 or
below.   Both quotes are for 4326 35G/15K disk units.

All comments/suggestions would be most appreciated.
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