1st Summary: Installing 2 ( E3500 + A5200 ) / High Availability -Reply

From: Seth Rothenberg (SROTHENB@montefiore.org)
Date: Fri Sep 03 1999 - 11:07:43 CDT


Thanks for all the replies. My question is at the bottom.

The most valuable reply I got was a footnote
on the reply from Tom Jones
    "BTW - you didn't mention the application to be hosted
    on the E3500 but if it is OLTP, stay FAR AWAY from the
    A5x00 array family!"
and his elaboration on that...
    "The A5x00 arrays don't have ANY cache. Don't get taken by the
    speed of the interface (FC-AL vs UWSCSI) - the type and size of
    I/O will limit the utilization of the bandwidth."

I am taking a close look at the A3500, though I really would
prefer a disk system that uses one of the on-board interfaces
rather than needing an UltraSCSI port which takes a slot:-)

On the subject of Cabinets, the consensus seems to be
to put the E3500's in a cabinet. Steve Turgeon wrote that
two 3500's will fit in one Sun cabinet, but recommended
against it. I will try to get 2 cabinets,
and put one E3500 on the bottom shelf of each cabinet,
because it is easier to ask 2 half-full cabinets in advance
than to ask for a second cabinet later. The cabinets will
not be joined together, per Travis Freeland's comment:

    "The concern with a dual width cabinet is that you will
    be sucking warm air out of one system and into the other
    as the airflow on the e3500 and a5x00 is from one side to
    the other (cant remember the direction off the top of my
    head)."

James Kwong <kwong@solar.acast.nova.edu>
mentioned that 'www.sharkrack.com' offers the E3500 rackmount kit.

"Luke A. Kanies" also had a suggestion...
    "...it may be a better solution to get 4500s. They cost a bit more
    initially, and they don't have internal drive space, but they have
    a lot more upgradeability in terms of power, and they are _much_ smaller.
    You could fit two of them and two a5200s inside a singe cabinet.
    Then you would just need an a1000 or disk trays for the boot disks.

>>> "Seth Rothenberg" <SROTHENB@montefiore.org> 08/30 2:43 pm >>>
My boss has charged me with spec'ing out a new system.
Working with Sun, I have quotes on a pair of
E3500's and 2 A5200's. However, I would like
recommendations from the group on 2 issues:
1. Physical installation and
2. Disk fibre cabling

Have people installed A3500's inside cabinets?
Or, do they put them on the floor? The concern
I have about the floor is that we have many
peripherals that belong within a cabinet.
(IBM Buss + Tagg cable, HSI/S, Multipacks).
The A3500 is quite heavy. Is the "Rack Mount"
option the best thing?

Maybe one E3500 and 2 A5200's in a cabinet,
and one 3500 on the floor? But, then the cables....

One thought is to buy two cabinets,
but only one set of walls, and it would
be like a double-wide cabinet.
I don't know if that will meet standards here.

The second question is how to arrange cables.
We are buying - iniitially - two 7-disk arrays.
I would like them to be easy to manage. We
don't generally make a lot of changes once
things are in - probably two 3-disk stripes
mirrored to two other 3-disk stripes on array 2.
We have a lot of experience with SDS
and its capabilities and limitations,
and with SINGLE connected disks. I don't
yet know all the ways the A5200's can be
connected. We may even want to bring the
old SS1000's into the FC/AL.

Thanks
Seth



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