RE: More disk arms myth exploded... -- MIDRANGE-L

John   understand SPD, I  was commenting  on use  in the 520 ( PCI-X)  system

At 03:09 PM 8/13/2004, Jones, John (US) wrote:

There aren't any LVD controllers for SPD systems so I had to go HVD.
Did the same on the 830 to keep the ability to move drives around in an
emergency.

We're looking at upgrading to 570s for both systems and if/when we do
I'll get the new 2780 DASD controllers and the new (forget the FC) tape
controllers.  And will swap the 3580s for LVD versions.  No use for
fiber here.  Will also standardize on 70GB 15K disks for both system;
about 50 to replace the 65 17GB disks in the current systems.  IBM
modelled it and said the workload should be do-able in 23-26 arms, but
I'm not willing to reduce the arm count that drastically.  (Besides, if
I _have_ to get the 5094 I may as well fill it up.)  I'm not sure what
I'll do with 3+TB DASD, although I'm sure the users will find a way to
fill it eventually.

John A. Jones
Americas Security Officer
Jones Lang LaSalle, Inc.
V: +1-630-455-2787 F: +1-312-601-1782
John.Jones@xxxxxxxxxxxxxxxxxxxxxxx

-----Original Message-----
From: Glenn Ericson [mailto:Glenn-Ericson@xxxxxxx]
Sent: Friday, August 13, 2004 1:58 PM
To: Midrange Systems Technical Discussion; 'midrange-l@xxxxxxxxxxxx'
Subject: RE: More disk arms myth exploded...

John  the H23 is the HDV  model. Try the L23 and the LDV controllers-
it  can   near match the speeds of  fiber . For  DASD  controllers  try
the  new 2780  controller over the  2757  with 1GB  read cache and757MB
write cache.  Another item was  a mix of several different DASD sizes
and rpm rates, which is not  a performance plus.

Frankly,  in a production system, I'd be challenged to cut back to 16%
of the  original arms and expect continued performance as  those  bigger
drives begin to fill  with  data  or trash.


>-----Original Message-----
>date: Fri, 13 Aug 2004 10:49:01 -0500
>from: "Jones, John (US)" <John.Jones@xxxxxxxxxxxxxxxxxxxxxxx>
>subject: RE: More disk arms myth exploded...
>
>
>I would guess #1: Tape controller.  On our 730 using 3580-H23 drives,
>saves at 70GB/hour over a 6534.  On our 830 using the same drive types
>but a 2729, we get 200GB/hour.  The machines have similar RAM, CPW, #
>disk arms, etc.  And really, more than the tape controller it's the SPD

>bus.
>
>You could also potentially mention the spreading of the data will be
>optimal on the 520 as it was a reload. But I don't think it would make
>that large of a difference.
>
>John A. Jones
>Americas Security Officer
>Jones Lang LaSalle, Inc.
>V: +1-630-455-2787 F: +1-312-601-1782
>John.Jones@xxxxxxxxxxxxxxxxxxxxxxx

This email is for the use of the intended recipient(s) only. If you have received this email in error, please notify the sender immediately and then delete it. If you are not the intended recipient, you must not keep, use, disclose, copy or distribute this email without the author's prior permission. We have taken precautions to minimize the risk of transmitting software viruses, but we advise you to carry out your own virus checks on any attachment to this message. We cannot accept liability for any loss or damage caused by software viruses. The information contained in this communication may be confidential and may be subject to the attorney-client privilege. If you are the intended recipient and you do not wish to receive similar electronic messages from us in future then please respond to the sender to this effect.

--
This is the Midrange Systems Technical Discussion (MIDRANGE-L) mailing list
To post a message email: MIDRANGE-L@xxxxxxxxxxxx
To subscribe, unsubscribe, or change list options,
visit: http://lists.midrange.com/mailman/listinfo/midrange-l
or email: MIDRANGE-L-request@xxxxxxxxxxxx
Before posting, please take a moment to review the archives
at http://archive.midrange.com/midrange-l.